diff --git a/demo/README.md b/demo/README.md
index 4b513123..7b87d905 100644
--- a/demo/README.md
+++ b/demo/README.md
@@ -26,5 +26,15 @@ Please refer to [End2End Demo](docs/ocr_demo.md) for the tutorial of Text Detect
     <img src="resources/demo_ocr_pred.jpg"/><br>
 
 </div>
+<br>
+<br>
+
+Please refer to [KIE End2End Demo](docs/kie_demo.md) for the tutorial of KIE end-to-end demo.
+
+<div align="center">
+    <img src="resources/demo_kie_pred.jpeg"/><br>
+
+</div>
+
 
 <br>
diff --git a/demo/demo_kie.jpeg b/demo/demo_kie.jpeg
new file mode 100755
index 00000000..51014d8e
Binary files /dev/null and b/demo/demo_kie.jpeg differ
diff --git a/demo/resources/demo_kie_pred.png b/demo/resources/demo_kie_pred.png
new file mode 100644
index 00000000..4a84d0c9
Binary files /dev/null and b/demo/resources/demo_kie_pred.png differ
diff --git a/docs/demo.md b/docs/demo.md
index 057de082..26653df0 100644
--- a/docs/demo.md
+++ b/docs/demo.md
@@ -70,7 +70,7 @@ results = ocr.readtext(%INPUT_FOLDER_PATH%, output = %OUTPUT_FOLDER_PATH%, batch
 ```shell
 python mmocr/utils/ocr.py demo/demo_text_ocr.jpg --print-result --imshow
 ```
-*Note: When calling the script from the command line, the `configs` folder must be in the current working directory.*
+*Note: When calling the script from the command line, the script assumes configs are saved in the `configs/` folder. User can customize the directory by specifying the value of `config_dir`. *
 
 - Python interface:
 ```python
@@ -84,6 +84,33 @@ results = ocr.readtext('demo/demo_text_ocr.jpg', print_result=True, imshow=True)
 ```
 ---
 
+## Example 4: Text Detection + Recognition + Key Information Extraction
+
+<div align="center">
+    <img src="https://raw.githubusercontent.com/open-mmlab/mmocr/main/demo/resources/demo_kie_pred.png"/><br>
+</div>
+<br>
+
+**Instruction:** Perform end-to-end ocr (det + recog) inference first with PS_CTW detection model and SAR recognition model, then run KIE inference with SDMGR model on the ocr result and show the visualization.
+
+- CL interface:
+```shell
+python mmocr/utils/ocr.py demo/demo_kie.jpeg  --det PS_CTW --recog SAR --kie SDMGR --print-result --imshow
+```
+*Note: When calling the script from the command line, the script assumes configs are saved in the `configs/` folder. User can customize the directory by specifying the value of `config_dir`. *
+
+- Python interface:
+```python
+from mmocr.utils.ocr import MMOCR
+
+# Load models into memory
+ocr = MMOCR(det='PS_CTW', recog='SAR', kie='SDMGR')
+
+# Inference
+results = ocr.readtext('demo/demo_kie.jpeg', print_result=True, imshow=True)
+```
+---
+
 ## API Arguments
 The API has an extensive list of arguments that you can use. The following tables are for the python interface.
 
@@ -91,16 +118,21 @@ The API has an extensive list of arguments that you can use. The following table
 
 | Arguments      | Type                  | Default       | Description                                                 |
 | -------------- | --------------------- | ------------- | ----------------------------------------------------------- |
-| `det`          | see [models](#models) | PANet_IC15 | Text detection algorithm                                    |
+| `det`          | see [models](#models) | PANet_IC15    | Text detection algorithm                                    |
 | `recog`        | see [models](#models) | SAR           | Text recognition algorithm                                  |
+| `kie` [1]      | see [models](#models) | None          | Key information extraction algorithm                                  |
 | `config_dir`   | str                   | configs/      | Path to the config directory where all the config files are located  |
 | `det_config`   | str                   | None          | Path to the custom config file of the selected det model         |
 | `det_ckpt`     | str                   | None          | Path to the custom checkpoint file of the selected det model         |
-| `recog_config` | str                   | None          | Path to the custom config file of the selected recog model model |
-| `recog_ckpt`   | str                   | None          | Path to the custom checkpoint file of the selected recog model model |
+| `recog_config` | str                   | None          | Path to the custom config file of the selected recog model |
+| `recog_ckpt`   | str                   | None          | Path to the custom checkpoint file of the selected recog model |
+| `kie_config`   | str                   | None          | Path to the custom config file of the selected kie model |
+| `kie_ckpt`     | str                   | None          | Path to the custom checkpoint file of the selected kie model |
 | `device`       | str                   | cuda:0        | Device used for inference: 'cuda:0' or 'cpu'                |
 
-**Note:** User can use default pretrained models by specifying `det` and/or `recog`, which is equivalent to setting `*_config` and `*_ckpt` as default values. However, manually specifying `*_config` and `*_ckpt` will always override default values set by `det` and/or `recog`.
+[1]: `kie` is only effective when both text detection and recognition models are specified.
+
+**Note:** User can use default pretrained models by specifying `det` and/or `recog`, which is equivalent to specifying their corresponding `*_config` and `*_ckpt`. However, manually specifying `*_config` and `*_ckpt` will always override values set by `det` and/or `recog`. Similar rules also apply to `kie`, `kie_config` and `kie_ckpt`.
 
 ### readtext():
 
@@ -117,8 +149,8 @@ The API has an extensive list of arguments that you can use. The following table
 | `details`           | bool                    | False        | Whether include the text boxes coordinates and confidence values       |
 | `imshow`            | bool                    | False        | Whether to show the result visualization on screen                     |
 | `print_result`      | bool                    | False        | Whether to show the result for each image                              |
-| `merge`      | bool                    | False        | Whether to merge neighboring boxes [2]                              |
-| `merge_xdist`      | float                    | 20        | The maximum x-axis distance to merge boxes                              |
+| `merge`             | bool                    | False        | Whether to merge neighboring boxes [2]                              |
+| `merge_xdist`       | float                   | 20           | The maximum x-axis distance to merge boxes                              |
 
 [1]: Make sure that the model is compatible with batch mode.
 
@@ -165,6 +197,11 @@ means that `batch_mode` and `print_result` are set to `True`)
 | SEG           | [link](https://mmocr.readthedocs.io/en/latest/textrecog_models.html#segocr-simple-baseline) |         :x:          |
 | CRNN_TPS      | [link](https://mmocr.readthedocs.io/en/latest/textrecog_models.html#crnn-with-tps-based-stn) |  :heavy_check_mark:  |
 
+**Key information extraction:**
+
+| Name          |                                                                        Reference                                                                         | `batch_mode` support |
+| ------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------: | :------------------: |
+| SDMGR         |            [link](https://mmocr.readthedocs.io/en/latest/kie_models.html#spatial-dual-modality-graph-reasoning-for-key-information-extraction)            |         :heavy_check_mark:          |
 ---
 
 ## Additional info
diff --git a/docs_zh_CN/demo.md b/docs_zh_CN/demo.md
index 057de082..26653df0 100644
--- a/docs_zh_CN/demo.md
+++ b/docs_zh_CN/demo.md
@@ -70,7 +70,7 @@ results = ocr.readtext(%INPUT_FOLDER_PATH%, output = %OUTPUT_FOLDER_PATH%, batch
 ```shell
 python mmocr/utils/ocr.py demo/demo_text_ocr.jpg --print-result --imshow
 ```
-*Note: When calling the script from the command line, the `configs` folder must be in the current working directory.*
+*Note: When calling the script from the command line, the script assumes configs are saved in the `configs/` folder. User can customize the directory by specifying the value of `config_dir`. *
 
 - Python interface:
 ```python
@@ -84,6 +84,33 @@ results = ocr.readtext('demo/demo_text_ocr.jpg', print_result=True, imshow=True)
 ```
 ---
 
+## Example 4: Text Detection + Recognition + Key Information Extraction
+
+<div align="center">
+    <img src="https://raw.githubusercontent.com/open-mmlab/mmocr/main/demo/resources/demo_kie_pred.png"/><br>
+</div>
+<br>
+
+**Instruction:** Perform end-to-end ocr (det + recog) inference first with PS_CTW detection model and SAR recognition model, then run KIE inference with SDMGR model on the ocr result and show the visualization.
+
+- CL interface:
+```shell
+python mmocr/utils/ocr.py demo/demo_kie.jpeg  --det PS_CTW --recog SAR --kie SDMGR --print-result --imshow
+```
+*Note: When calling the script from the command line, the script assumes configs are saved in the `configs/` folder. User can customize the directory by specifying the value of `config_dir`. *
+
+- Python interface:
+```python
+from mmocr.utils.ocr import MMOCR
+
+# Load models into memory
+ocr = MMOCR(det='PS_CTW', recog='SAR', kie='SDMGR')
+
+# Inference
+results = ocr.readtext('demo/demo_kie.jpeg', print_result=True, imshow=True)
+```
+---
+
 ## API Arguments
 The API has an extensive list of arguments that you can use. The following tables are for the python interface.
 
@@ -91,16 +118,21 @@ The API has an extensive list of arguments that you can use. The following table
 
 | Arguments      | Type                  | Default       | Description                                                 |
 | -------------- | --------------------- | ------------- | ----------------------------------------------------------- |
-| `det`          | see [models](#models) | PANet_IC15 | Text detection algorithm                                    |
+| `det`          | see [models](#models) | PANet_IC15    | Text detection algorithm                                    |
 | `recog`        | see [models](#models) | SAR           | Text recognition algorithm                                  |
+| `kie` [1]      | see [models](#models) | None          | Key information extraction algorithm                                  |
 | `config_dir`   | str                   | configs/      | Path to the config directory where all the config files are located  |
 | `det_config`   | str                   | None          | Path to the custom config file of the selected det model         |
 | `det_ckpt`     | str                   | None          | Path to the custom checkpoint file of the selected det model         |
-| `recog_config` | str                   | None          | Path to the custom config file of the selected recog model model |
-| `recog_ckpt`   | str                   | None          | Path to the custom checkpoint file of the selected recog model model |
+| `recog_config` | str                   | None          | Path to the custom config file of the selected recog model |
+| `recog_ckpt`   | str                   | None          | Path to the custom checkpoint file of the selected recog model |
+| `kie_config`   | str                   | None          | Path to the custom config file of the selected kie model |
+| `kie_ckpt`     | str                   | None          | Path to the custom checkpoint file of the selected kie model |
 | `device`       | str                   | cuda:0        | Device used for inference: 'cuda:0' or 'cpu'                |
 
-**Note:** User can use default pretrained models by specifying `det` and/or `recog`, which is equivalent to setting `*_config` and `*_ckpt` as default values. However, manually specifying `*_config` and `*_ckpt` will always override default values set by `det` and/or `recog`.
+[1]: `kie` is only effective when both text detection and recognition models are specified.
+
+**Note:** User can use default pretrained models by specifying `det` and/or `recog`, which is equivalent to specifying their corresponding `*_config` and `*_ckpt`. However, manually specifying `*_config` and `*_ckpt` will always override values set by `det` and/or `recog`. Similar rules also apply to `kie`, `kie_config` and `kie_ckpt`.
 
 ### readtext():
 
@@ -117,8 +149,8 @@ The API has an extensive list of arguments that you can use. The following table
 | `details`           | bool                    | False        | Whether include the text boxes coordinates and confidence values       |
 | `imshow`            | bool                    | False        | Whether to show the result visualization on screen                     |
 | `print_result`      | bool                    | False        | Whether to show the result for each image                              |
-| `merge`      | bool                    | False        | Whether to merge neighboring boxes [2]                              |
-| `merge_xdist`      | float                    | 20        | The maximum x-axis distance to merge boxes                              |
+| `merge`             | bool                    | False        | Whether to merge neighboring boxes [2]                              |
+| `merge_xdist`       | float                   | 20           | The maximum x-axis distance to merge boxes                              |
 
 [1]: Make sure that the model is compatible with batch mode.
 
@@ -165,6 +197,11 @@ means that `batch_mode` and `print_result` are set to `True`)
 | SEG           | [link](https://mmocr.readthedocs.io/en/latest/textrecog_models.html#segocr-simple-baseline) |         :x:          |
 | CRNN_TPS      | [link](https://mmocr.readthedocs.io/en/latest/textrecog_models.html#crnn-with-tps-based-stn) |  :heavy_check_mark:  |
 
+**Key information extraction:**
+
+| Name          |                                                                        Reference                                                                         | `batch_mode` support |
+| ------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------: | :------------------: |
+| SDMGR         |            [link](https://mmocr.readthedocs.io/en/latest/kie_models.html#spatial-dual-modality-graph-reasoning-for-key-information-extraction)            |         :heavy_check_mark:          |
 ---
 
 ## Additional info
diff --git a/mmocr/apis/inference.py b/mmocr/apis/inference.py
index 00ef7272..be979343 100644
--- a/mmocr/apis/inference.py
+++ b/mmocr/apis/inference.py
@@ -30,7 +30,11 @@ def disable_text_recog_aug_test(cfg, set_types=None):
     return cfg
 
 
-def model_inference(model, imgs, batch_mode=False):
+def model_inference(model,
+                    imgs,
+                    ann=None,
+                    batch_mode=False,
+                    return_data=False):
     """Inference image(s) with the detector.
 
     Args:
@@ -38,6 +42,8 @@ def model_inference(model, imgs, batch_mode=False):
         imgs (str/ndarray or list[str/ndarray] or tuple[str/ndarray]):
             Either image files or loaded images.
         batch_mode (bool): If True, use batch mode for inference.
+        ann (dict): Annotation info for key information extraction.
+        return_data: Return postprocessed data.
     Returns:
         result (dict): Predicted results.
     """
@@ -75,10 +81,14 @@ def model_inference(model, imgs, batch_mode=False):
         # prepare data
         if is_ndarray:
             # directly add img
-            data = dict(img=img)
+            data = dict(img=img, ann_info=ann, bbox_fields=[])
         else:
             # add information into dict
-            data = dict(img_info=dict(filename=img), img_prefix=None)
+            data = dict(
+                img_info=dict(filename=img),
+                img_prefix=None,
+                ann_info=ann,
+                bbox_fields=[])
 
         # build the data pipeline
         data = test_pipeline(data)
@@ -111,6 +121,14 @@ def model_inference(model, imgs, batch_mode=False):
     else:
         data['img'] = data['img'].data
 
+    # for KIE models
+    if ann is not None:
+        data['relations'] = data['relations'].data[0]
+        data['gt_bboxes'] = data['gt_bboxes'].data[0]
+        data['texts'] = data['texts'].data[0]
+        data['img'] = data['img'][0]
+        data['img_metas'] = data['img_metas'][0]
+
     if next(model.parameters()).is_cuda:
         # scatter to specified GPU
         data = scatter(data, [device])[0]
@@ -125,9 +143,13 @@ def model_inference(model, imgs, batch_mode=False):
         results = model(return_loss=False, rescale=True, **data)
 
     if not is_batch:
-        return results[0]
+        if not return_data:
+            return results[0]
+        return results[0], datas[0]
     else:
-        return results
+        if not return_data:
+            return results
+        return results, datas
 
 
 def text_model_inference(model, input_sentence):
diff --git a/mmocr/datasets/kie_dataset.py b/mmocr/datasets/kie_dataset.py
index 4c959900..566e4eaa 100644
--- a/mmocr/datasets/kie_dataset.py
+++ b/mmocr/datasets/kie_dataset.py
@@ -1,4 +1,5 @@
 import copy
+import warnings
 from os import path as osp
 
 import numpy as np
@@ -28,22 +29,28 @@ class KIEDataset(BaseDataset):
     """
 
     def __init__(self,
-                 ann_file,
-                 loader,
-                 dict_file,
+                 ann_file=None,
+                 loader=None,
+                 dict_file=None,
                  img_prefix='',
                  pipeline=None,
                  norm=10.,
                  directed=False,
                  test_mode=True,
                  **kwargs):
-        super().__init__(
-            ann_file,
-            loader,
-            pipeline,
-            img_prefix=img_prefix,
-            test_mode=test_mode)
-        assert osp.exists(dict_file)
+        if ann_file is None and loader is None:
+            warnings.warn(
+                'KIEDataset is only initialized as a downstream demo task '
+                'of text detection and recognition '
+                'without an annotation file.', UserWarning)
+        else:
+            super().__init__(
+                ann_file,
+                loader,
+                pipeline,
+                img_prefix=img_prefix,
+                test_mode=test_mode)
+            assert osp.exists(dict_file)
 
         self.norm = norm
         self.directed = directed
diff --git a/mmocr/utils/ocr.py b/mmocr/utils/ocr.py
index 3130bac9..85d9f9a9 100644
--- a/mmocr/utils/ocr.py
+++ b/mmocr/utils/ocr.py
@@ -1,3 +1,4 @@
+import copy
 import os
 import warnings
 from argparse import ArgumentParser, Namespace
@@ -5,288 +6,19 @@ from pathlib import Path
 
 import mmcv
 import numpy as np
+import torch
+from mmcv.image.misc import tensor2imgs
+from mmcv.runner import load_checkpoint
+from mmcv.utils.config import Config
 from mmdet.apis import init_detector
 
 from mmocr.apis.inference import model_inference
 from mmocr.core.visualize import det_recog_show_result
+from mmocr.datasets.kie_dataset import KIEDataset
 from mmocr.datasets.pipelines.crop import crop_img
+from mmocr.models import build_detector
 from mmocr.utils.box_util import stitch_boxes_into_lines
-
-textdet_models = {
-    'DB_r18': {
-        'config': 'dbnet/dbnet_r18_fpnc_1200e_icdar2015.py',
-        'ckpt':
-        'dbnet/dbnet_r18_fpnc_sbn_1200e_icdar2015_20210329-ba3ab597.pth'
-    },
-    'DB_r50': {
-        'config':
-        'dbnet/dbnet_r50dcnv2_fpnc_1200e_icdar2015.py',
-        'ckpt':
-        'dbnet/dbnet_r50dcnv2_fpnc_sbn_1200e_icdar2015_20210325-91cef9af.pth'
-    },
-    'DRRG': {
-        'config': 'drrg/drrg_r50_fpn_unet_1200e_ctw1500.py',
-        'ckpt': 'drrg/drrg_r50_fpn_unet_1200e_ctw1500-1abf4f67.pth'
-    },
-    'FCE_IC15': {
-        'config': 'fcenet/fcenet_r50_fpn_1500e_icdar2015.py',
-        'ckpt': 'fcenet/fcenet_r50_fpn_1500e_icdar2015-d435c061.pth'
-    },
-    'FCE_CTW_DCNv2': {
-        'config': 'fcenet/fcenet_r50dcnv2_fpn_1500e_ctw1500.py',
-        'ckpt': 'fcenet/fcenet_r50dcnv2_fpn_1500e_ctw1500-05d740bb.pth'
-    },
-    'MaskRCNN_CTW': {
-        'config': 'maskrcnn/mask_rcnn_r50_fpn_160e_ctw1500.py',
-        'ckpt': 'maskrcnn/mask_rcnn_r50_fpn_160e_ctw1500_20210219-96497a76.pth'
-    },
-    'MaskRCNN_IC15': {
-        'config': 'maskrcnn/mask_rcnn_r50_fpn_160e_icdar2015.py',
-        'ckpt':
-        'maskrcnn/mask_rcnn_r50_fpn_160e_icdar2015_20210219-8eb340a3.pth'
-    },
-    'MaskRCNN_IC17': {
-        'config': 'maskrcnn/mask_rcnn_r50_fpn_160e_icdar2017.py',
-        'ckpt':
-        'maskrcnn/mask_rcnn_r50_fpn_160e_icdar2017_20210218-c6ec3ebb.pth'
-    },
-    'PANet_CTW': {
-        'config': 'panet/panet_r18_fpem_ffm_600e_ctw1500.py',
-        'ckpt':
-        'panet/panet_r18_fpem_ffm_sbn_600e_ctw1500_20210219-3b3a9aa3.pth'
-    },
-    'PANet_IC15': {
-        'config': 'panet/panet_r18_fpem_ffm_600e_icdar2015.py',
-        'ckpt':
-        'panet/panet_r18_fpem_ffm_sbn_600e_icdar2015_20210219-42dbe46a.pth'
-    },
-    'PS_CTW': {
-        'config': 'psenet/psenet_r50_fpnf_600e_ctw1500.py',
-        'ckpt': 'psenet/psenet_r50_fpnf_600e_ctw1500_20210401-216fed50.pth'
-    },
-    'PS_IC15': {
-        'config': 'psenet/psenet_r50_fpnf_600e_icdar2015.py',
-        'ckpt': 'psenet/psenet_r50_fpnf_600e_icdar2015_pretrain-eefd8fe6.pth'
-    },
-    'TextSnake': {
-        'config': 'textsnake/textsnake_r50_fpn_unet_1200e_ctw1500.py',
-        'ckpt': 'textsnake/textsnake_r50_fpn_unet_1200e_ctw1500-27f65b64.pth'
-    }
-}
-
-textrecog_models = {
-    'CRNN': {
-        'config': 'crnn/crnn_academic_dataset.py',
-        'ckpt': 'crnn/crnn_academic-a723a1c5.pth'
-    },
-    'SAR': {
-        'config': 'sar/sar_r31_parallel_decoder_academic.py',
-        'ckpt': 'sar/sar_r31_parallel_decoder_academic-dba3a4a3.pth'
-    },
-    'NRTR_1/16-1/8': {
-        'config': 'nrtr/nrtr_r31_1by16_1by8_academic.py',
-        'ckpt': 'nrtr/nrtr_r31_academic_20210406-954db95e.pth'
-    },
-    'NRTR_1/8-1/4': {
-        'config': 'nrtr/nrtr_r31_1by8_1by4_academic.py',
-        'ckpt': 'nrtr/nrtr_r31_1by8_1by4_academic_20210406-ce16e7cc.pth'
-    },
-    'RobustScanner': {
-        'config': 'robust_scanner/robustscanner_r31_academic.py',
-        'ckpt': 'robust_scanner/robustscanner_r31_academic-5f05874f.pth'
-    },
-    'SEG': {
-        'config': 'seg/seg_r31_1by16_fpnocr_academic.py',
-        'ckpt': 'seg/seg_r31_1by16_fpnocr_academic-72235b11.pth'
-    },
-    'CRNN_TPS': {
-        'config': 'tps/crnn_tps_academic_dataset.py',
-        'ckpt': 'tps/crnn_tps_academic_dataset_20210510-d221a905.pth'
-    }
-}
-
-
-# Post processing function for end2end ocr
-def det_recog_pp(args, result):
-    final_results = []
-    for arr, output, export, det_recog_result in zip(args.arrays, args.output,
-                                                     args.export, result):
-        if output or args.imshow:
-            res_img = det_recog_show_result(
-                arr, det_recog_result, out_file=output)
-            if args.imshow:
-                mmcv.imshow(res_img, 'inference results')
-        if not args.details:
-            simple_res = {}
-            simple_res['filename'] = det_recog_result['filename']
-            simple_res['text'] = [
-                x['text'] for x in det_recog_result['result']
-            ]
-            final_result = simple_res
-        else:
-            final_result = det_recog_result
-        if export:
-            mmcv.dump(final_result, export, indent=4)
-        if args.print_result:
-            print(final_result, end='\n\n')
-        final_results.append(final_result)
-    return final_results
-
-
-# Post processing function for separate det/recog inference
-def single_pp(args, result, model):
-    for arr, output, export, res in zip(args.arrays, args.output, args.export,
-                                        result):
-        if export:
-            mmcv.dump(res, export, indent=4)
-        if output or args.imshow:
-            res_img = model.show_result(arr, res, out_file=output)
-            if args.imshow:
-                mmcv.imshow(res_img, 'inference results')
-        if args.print_result:
-            print(res, end='\n\n')
-    return result
-
-
-# End2end ocr inference pipeline
-def det_and_recog_inference(args, det_model, recog_model):
-    end2end_res = []
-    # Find bounding boxes in the images (text detection)
-    det_result = single_inference(det_model, args.arrays, args.batch_mode,
-                                  args.det_batch_size)
-    bboxes_list = [res['boundary_result'] for res in det_result]
-
-    # For each bounding box, the image is cropped and sent to the recognition
-    # model either one by one or all together depending on the batch_mode
-    for filename, arr, bboxes in zip(args.filenames, args.arrays, bboxes_list):
-        img_e2e_res = {}
-        img_e2e_res['filename'] = filename
-        img_e2e_res['result'] = []
-        box_imgs = []
-        for bbox in bboxes:
-            box_res = {}
-            box_res['box'] = [round(x) for x in bbox[:-1]]
-            box_res['box_score'] = float(bbox[-1])
-            box = bbox[:8]
-            if len(bbox) > 9:
-                min_x = min(bbox[0:-1:2])
-                min_y = min(bbox[1:-1:2])
-                max_x = max(bbox[0:-1:2])
-                max_y = max(bbox[1:-1:2])
-                box = [min_x, min_y, max_x, min_y, max_x, max_y, min_x, max_y]
-            box_img = crop_img(arr, box)
-            if args.batch_mode:
-                box_imgs.append(box_img)
-            else:
-                recog_result = model_inference(recog_model, box_img)
-                text = recog_result['text']
-                text_score = recog_result['score']
-                if isinstance(text_score, list):
-                    text_score = sum(text_score) / max(1, len(text))
-                box_res['text'] = text
-                box_res['text_score'] = text_score
-            img_e2e_res['result'].append(box_res)
-
-        if args.batch_mode:
-            recog_results = single_inference(recog_model, box_imgs, True,
-                                             args.recog_batch_size)
-            for i, recog_result in enumerate(recog_results):
-                text = recog_result['text']
-                text_score = recog_result['score']
-                if isinstance(text_score, (list, tuple)):
-                    text_score = sum(text_score) / max(1, len(text))
-                img_e2e_res['result'][i]['text'] = text
-                img_e2e_res['result'][i]['text_score'] = text_score
-
-        if args.merge:
-            img_e2e_res['result'] = stitch_boxes_into_lines(
-                img_e2e_res['result'], args.merge_xdist, 0.5)
-
-        end2end_res.append(img_e2e_res)
-    return end2end_res
-
-
-# Separate det/recog inference pipeline
-def single_inference(model, arrays, batch_mode, batch_size):
-    result = []
-    if batch_mode:
-        if batch_size == 0:
-            result = model_inference(model, arrays, batch_mode=True)
-        else:
-            n = batch_size
-            arr_chunks = [arrays[i:i + n] for i in range(0, len(arrays), n)]
-            for chunk in arr_chunks:
-                result.extend(model_inference(model, chunk, batch_mode=True))
-    else:
-        for arr in arrays:
-            result.append(model_inference(model, arr, batch_mode=False))
-    return result
-
-
-# Arguments pre-processing function
-def args_processing(args):
-    # Check if the input is a list/tuple that
-    # contains only np arrays or strings
-    if isinstance(args.img, (list, tuple)):
-        img_list = args.img
-        if not all([isinstance(x, (np.ndarray, str)) for x in args.img]):
-            raise AssertionError('Images must be strings or numpy arrays')
-
-    # Create a list of the images
-    if isinstance(args.img, str):
-        img_path = Path(args.img)
-        if img_path.is_dir():
-            img_list = [str(x) for x in img_path.glob('*')]
-        else:
-            img_list = [str(img_path)]
-    elif isinstance(args.img, np.ndarray):
-        img_list = [args.img]
-
-    # Read all image(s) in advance to reduce wasted time
-    # re-reading the images for vizualisation output
-    args.arrays = [mmcv.imread(x) for x in img_list]
-
-    # Create a list of filenames (used for output images and result files)
-    if isinstance(img_list[0], str):
-        args.filenames = [str(Path(x).stem) for x in img_list]
-    else:
-        args.filenames = [str(x) for x in range(len(img_list))]
-
-    # If given an output argument, create a list of output image filenames
-    num_res = len(img_list)
-    if args.output:
-        output_path = Path(args.output)
-        if output_path.is_dir():
-            args.output = [
-                str(output_path / f'out_{x}.png') for x in args.filenames
-            ]
-        else:
-            args.output = [str(args.output)]
-            if args.batch_mode:
-                raise AssertionError(
-                    'Output of multiple images inference must be a directory')
-    else:
-        args.output = [None] * num_res
-
-    # If given an export argument, create a list of
-    # result filenames for each image
-    if args.export:
-        export_path = Path(args.export)
-        args.export = [
-            str(export_path / f'out_{x}.{args.export_format}')
-            for x in args.filenames
-        ]
-    else:
-        args.export = [None] * num_res
-
-    return args
-
-
-# Create an inference pipeline with parsed arguments
-def main():
-    args = parse_args()
-    ocr = MMOCR(**vars(args))
-    ocr.readtext(**vars(args))
+from mmocr.utils.fileio import list_from_file
 
 
 # Parse CLI arguments
@@ -333,6 +65,23 @@ def parse_args():
         default='',
         help='Path to the custom checkpoint file of the selected recog model. '
         'It overrides the settings in recog')
+    parser.add_argument(
+        '--kie',
+        type=str,
+        default='',
+        help='Pretrained key information extraction algorithm')
+    parser.add_argument(
+        '--kie-config',
+        type=str,
+        default='',
+        help='Path to the custom config file of the selected kie model. It'
+        'overrides the settings in kie')
+    parser.add_argument(
+        '--kie-ckpt',
+        type=str,
+        default='',
+        help='Path to the custom checkpoint file of the selected kie model. '
+        'It overrides the settings in kie')
     parser.add_argument(
         '--config-dir',
         type=str,
@@ -418,11 +167,138 @@ class MMOCR:
                  recog='SEG',
                  recog_config='',
                  recog_ckpt='',
+                 kie='',
+                 kie_config='',
+                 kie_ckpt='',
                  config_dir=os.path.join(str(Path.cwd()), 'configs/'),
                  device='cuda:0',
                  **kwargs):
+
+        textdet_models = {
+            'DB_r18': {
+                'config':
+                'dbnet/dbnet_r18_fpnc_1200e_icdar2015.py',
+                'ckpt':
+                'dbnet/'
+                'dbnet_r18_fpnc_sbn_1200e_icdar2015_20210329-ba3ab597.pth'
+            },
+            'DB_r50': {
+                'config':
+                'dbnet/dbnet_r50dcnv2_fpnc_1200e_icdar2015.py',
+                'ckpt':
+                'dbnet/'
+                'dbnet_r50dcnv2_fpnc_sbn_1200e_icdar2015_20210325-91cef9af.pth'
+            },
+            'DRRG': {
+                'config': 'drrg/drrg_r50_fpn_unet_1200e_ctw1500.py',
+                'ckpt': 'drrg/drrg_r50_fpn_unet_1200e_ctw1500-1abf4f67.pth'
+            },
+            'FCE_IC15': {
+                'config': 'fcenet/fcenet_r50_fpn_1500e_icdar2015.py',
+                'ckpt': 'fcenet/fcenet_r50_fpn_1500e_icdar2015-d435c061.pth'
+            },
+            'FCE_CTW_DCNv2': {
+                'config': 'fcenet/fcenet_r50dcnv2_fpn_1500e_ctw1500.py',
+                'ckpt': 'fcenet/fcenet_r50dcnv2_fpn_1500e_ctw1500-05d740bb.pth'
+            },
+            'MaskRCNN_CTW': {
+                'config':
+                'maskrcnn/mask_rcnn_r50_fpn_160e_ctw1500.py',
+                'ckpt':
+                'maskrcnn/'
+                'mask_rcnn_r50_fpn_160e_ctw1500_20210219-96497a76.pth'
+            },
+            'MaskRCNN_IC15': {
+                'config':
+                'maskrcnn/mask_rcnn_r50_fpn_160e_icdar2015.py',
+                'ckpt':
+                'maskrcnn/'
+                'mask_rcnn_r50_fpn_160e_icdar2015_20210219-8eb340a3.pth'
+            },
+            'MaskRCNN_IC17': {
+                'config':
+                'maskrcnn/mask_rcnn_r50_fpn_160e_icdar2017.py',
+                'ckpt':
+                'maskrcnn/'
+                'mask_rcnn_r50_fpn_160e_icdar2017_20210218-c6ec3ebb.pth'
+            },
+            'PANet_CTW': {
+                'config':
+                'panet/panet_r18_fpem_ffm_600e_ctw1500.py',
+                'ckpt':
+                'panet/'
+                'panet_r18_fpem_ffm_sbn_600e_ctw1500_20210219-3b3a9aa3.pth'
+            },
+            'PANet_IC15': {
+                'config':
+                'panet/panet_r18_fpem_ffm_600e_icdar2015.py',
+                'ckpt':
+                'panet/'
+                'panet_r18_fpem_ffm_sbn_600e_icdar2015_20210219-42dbe46a.pth'
+            },
+            'PS_CTW': {
+                'config': 'psenet/psenet_r50_fpnf_600e_ctw1500.py',
+                'ckpt':
+                'psenet/psenet_r50_fpnf_600e_ctw1500_20210401-216fed50.pth'
+            },
+            'PS_IC15': {
+                'config':
+                'psenet/psenet_r50_fpnf_600e_icdar2015.py',
+                'ckpt':
+                'psenet/psenet_r50_fpnf_600e_icdar2015_pretrain-eefd8fe6.pth'
+            },
+            'TextSnake': {
+                'config':
+                'textsnake/textsnake_r50_fpn_unet_1200e_ctw1500.py',
+                'ckpt':
+                'textsnake/textsnake_r50_fpn_unet_1200e_ctw1500-27f65b64.pth'
+            }
+        }
+
+        textrecog_models = {
+            'CRNN': {
+                'config': 'crnn/crnn_academic_dataset.py',
+                'ckpt': 'crnn/crnn_academic-a723a1c5.pth'
+            },
+            'SAR': {
+                'config': 'sar/sar_r31_parallel_decoder_academic.py',
+                'ckpt': 'sar/sar_r31_parallel_decoder_academic-dba3a4a3.pth'
+            },
+            'NRTR_1/16-1/8': {
+                'config': 'nrtr/nrtr_r31_1by16_1by8_academic.py',
+                'ckpt': 'nrtr/nrtr_r31_academic_20210406-954db95e.pth'
+            },
+            'NRTR_1/8-1/4': {
+                'config': 'nrtr/nrtr_r31_1by8_1by4_academic.py',
+                'ckpt':
+                'nrtr/nrtr_r31_1by8_1by4_academic_20210406-ce16e7cc.pth'
+            },
+            'RobustScanner': {
+                'config': 'robust_scanner/robustscanner_r31_academic.py',
+                'ckpt':
+                'robust_scanner/robustscanner_r31_academic-5f05874f.pth'
+            },
+            'SEG': {
+                'config': 'seg/seg_r31_1by16_fpnocr_academic.py',
+                'ckpt': 'seg/seg_r31_1by16_fpnocr_academic-72235b11.pth'
+            },
+            'CRNN_TPS': {
+                'config': 'tps/crnn_tps_academic_dataset.py',
+                'ckpt': 'tps/crnn_tps_academic_dataset_20210510-d221a905.pth'
+            }
+        }
+
+        kie_models = {
+            'SDMGR': {
+                'config': 'sdmgr/sdmgr_unet16_60e_wildreceipt.py',
+                'ckpt':
+                'sdmgr/sdmgr_unet16_60e_wildreceipt_20210520-7489e6de.pth'
+            }
+        }
+
         self.td = det
         self.tr = recog
+        self.kie = kie
         self.device = device
 
         # Check if the det/recog model choice is valid
@@ -432,7 +308,12 @@ class MMOCR:
         elif self.tr and self.tr not in textrecog_models:
             raise ValueError(self.tr,
                              'is not a supported text recognition algorithm')
+        elif self.kie and self.kie not in kie_models:
+            raise ValueError(
+                self.kie, 'is not a supported key information extraction'
+                ' algorithm')
 
+        self.detect_model = None
         if self.td:
             # Build detection model
             if not det_config:
@@ -444,9 +325,8 @@ class MMOCR:
 
             self.detect_model = init_detector(
                 det_config, det_ckpt, device=self.device)
-        else:
-            self.detect_model = None
 
+        self.recog_model = None
         if self.tr:
             # Build recognition model
             if not recog_config:
@@ -454,13 +334,27 @@ class MMOCR:
                     config_dir, 'textrecog/',
                     textrecog_models[self.tr]['config'])
             if not recog_ckpt:
-                recog_ckpt = 'https://download.openmmlab.com/mmocr/'
-                'textrecog/' + textrecog_models[self.tr]['ckpt']
+                recog_ckpt = 'https://download.openmmlab.com/mmocr/' + \
+                    'textrecog/' + textrecog_models[self.tr]['ckpt']
 
             self.recog_model = init_detector(
                 recog_config, recog_ckpt, device=self.device)
-        else:
-            self.recog_model = None
+
+        self.kie_model = None
+        if self.kie:
+            # Build key information extraction model
+            if not kie_config:
+                kie_config = os.path.join(config_dir, 'kie/',
+                                          kie_models[self.kie]['config'])
+            if not kie_ckpt:
+                kie_ckpt = 'https://download.openmmlab.com/mmocr/' + \
+                    'kie/' + kie_models[self.kie]['ckpt']
+
+            kie_cfg = Config.fromfile(kie_config)
+            self.kie_model = build_detector(
+                kie_cfg.model, test_cfg=kie_cfg.get('test_cfg'))
+            self.kie_model.cfg = kie_cfg
+            load_checkpoint(self.kie_model, kie_ckpt, map_location=self.device)
 
         # Attribute check
         for model in list(filter(None, [self.recog_model, self.detect_model])):
@@ -490,25 +384,292 @@ class MMOCR:
         args = Namespace(**args)
 
         # Input and output arguments processing
-        args = args_processing(args)
+        self._args_processing(args)
+        self.args = args
 
         pp_result = None
 
         # Send args and models to the MMOCR model inference API
         # and call post-processing functions for the output
         if self.detect_model and self.recog_model:
-            det_recog_result = det_and_recog_inference(args, self.detect_model,
-                                                       self.recog_model)
-            pp_result = det_recog_pp(args, det_recog_result)
+            det_recog_result = self.det_recog_kie_inference(
+                self.detect_model, self.recog_model, kie_model=self.kie_model)
+            pp_result = self.det_recog_pp(det_recog_result)
         else:
             for model in list(
                     filter(None, [self.recog_model, self.detect_model])):
-                result = single_inference(model, args.arrays, args.batch_mode,
-                                          args.single_batch_size)
-                pp_result = single_pp(args, result, model)
+                result = self.single_inference(model, args.arrays,
+                                               args.batch_mode,
+                                               args.single_batch_size)
+                pp_result = self.single_pp(args, result, model)
 
         return pp_result
 
+    # Post processing function for end2end ocr
+    def det_recog_pp(self, result):
+        final_results = []
+        args = self.args
+        for arr, output, export, det_recog_result in zip(
+                args.arrays, args.output, args.export, result):
+            if output or args.imshow:
+                if self.kie_model:
+                    res_img = det_recog_show_result(arr, det_recog_result)
+                else:
+                    res_img = det_recog_show_result(
+                        arr, det_recog_result, out_file=output)
+                if args.imshow and not self.kie_model:
+                    mmcv.imshow(res_img, 'inference results')
+            if not args.details:
+                simple_res = {}
+                simple_res['filename'] = det_recog_result['filename']
+                simple_res['text'] = [
+                    x['text'] for x in det_recog_result['result']
+                ]
+                final_result = simple_res
+            else:
+                final_result = det_recog_result
+            if export:
+                mmcv.dump(final_result, export, indent=4)
+            if args.print_result:
+                print(final_result, end='\n\n')
+            final_results.append(final_result)
+        return final_results
+
+    # Post processing function for separate det/recog inference
+    def single_pp(self, result, model):
+        for arr, output, export, res in zip(self.args.arrays, self.args.output,
+                                            self.args.export, result):
+            if export:
+                mmcv.dump(res, export, indent=4)
+            if output or self.args.imshow:
+                res_img = model.show_result(arr, res, out_file=output)
+                if self.args.imshow:
+                    mmcv.imshow(res_img, 'inference results')
+            if self.args.print_result:
+                print(res, end='\n\n')
+        return result
+
+    def generate_kie_labels(self, result, boxes, class_list):
+        idx_to_cls = {}
+        if class_list is not None:
+            for line in list_from_file(class_list):
+                class_idx, class_label = line.strip().split()
+                idx_to_cls[class_idx] = class_label
+
+        max_value, max_idx = torch.max(result['nodes'].detach().cpu(), -1)
+        node_pred_label = max_idx.numpy().tolist()
+        node_pred_score = max_value.numpy().tolist()
+        labels = []
+        for i in range(len(boxes)):
+            pred_label = str(node_pred_label[i])
+            if pred_label in idx_to_cls:
+                pred_label = idx_to_cls[pred_label]
+            pred_score = node_pred_score[i]
+            labels.append((pred_label, pred_score))
+        return labels
+
+    def visualize_kie_output(self,
+                             model,
+                             data,
+                             result,
+                             out_file=None,
+                             show=False):
+        """Visualizes KIE output."""
+        img_tensor = data['img'].data
+        img_meta = data['img_metas'].data
+        gt_bboxes = data['gt_bboxes'].data.numpy().tolist()
+        img = tensor2imgs(img_tensor.unsqueeze(0),
+                          **img_meta['img_norm_cfg'])[0]
+        h, w, _ = img_meta['img_shape']
+        img_show = img[:h, :w, :]
+        model.show_result(
+            img_show, result, gt_bboxes, show=show, out_file=out_file)
+
+    # End2end ocr inference pipeline
+    def det_recog_kie_inference(self, det_model, recog_model, kie_model=None):
+        end2end_res = []
+        # Find bounding boxes in the images (text detection)
+        det_result = self.single_inference(det_model, self.args.arrays,
+                                           self.args.batch_mode,
+                                           self.args.det_batch_size)
+        bboxes_list = [res['boundary_result'] for res in det_result]
+
+        if kie_model:
+            kie_dataset = KIEDataset(
+                dict_file=kie_model.cfg.data.test.dict_file)
+
+        # For each bounding box, the image is cropped and
+        # sent to the recognition model either one by one
+        # or all together depending on the batch_mode
+        for filename, arr, bboxes, out_file in zip(self.args.filenames,
+                                                   self.args.arrays,
+                                                   bboxes_list,
+                                                   self.args.output):
+            img_e2e_res = {}
+            img_e2e_res['filename'] = filename
+            img_e2e_res['result'] = []
+            box_imgs = []
+            for bbox in bboxes:
+                box_res = {}
+                box_res['box'] = [round(x) for x in bbox[:-1]]
+                box_res['box_score'] = float(bbox[-1])
+                box = bbox[:8]
+                if len(bbox) > 9:
+                    min_x = min(bbox[0:-1:2])
+                    min_y = min(bbox[1:-1:2])
+                    max_x = max(bbox[0:-1:2])
+                    max_y = max(bbox[1:-1:2])
+                    box = [
+                        min_x, min_y, max_x, min_y, max_x, max_y, min_x, max_y
+                    ]
+                box_img = crop_img(arr, box)
+                if self.args.batch_mode:
+                    box_imgs.append(box_img)
+                else:
+                    recog_result = model_inference(recog_model, box_img)
+                    text = recog_result['text']
+                    text_score = recog_result['score']
+                    if isinstance(text_score, list):
+                        text_score = sum(text_score) / max(1, len(text))
+                    box_res['text'] = text
+                    box_res['text_score'] = text_score
+                img_e2e_res['result'].append(box_res)
+
+            if self.args.batch_mode:
+                recog_results = self.single_inference(
+                    recog_model, box_imgs, True, self.args.recog_batch_size)
+                for i, recog_result in enumerate(recog_results):
+                    text = recog_result['text']
+                    text_score = recog_result['score']
+                    if isinstance(text_score, (list, tuple)):
+                        text_score = sum(text_score) / max(1, len(text))
+                    img_e2e_res['result'][i]['text'] = text
+                    img_e2e_res['result'][i]['text_score'] = text_score
+
+            if self.args.merge:
+                img_e2e_res['result'] = stitch_boxes_into_lines(
+                    img_e2e_res['result'], self.args.merge_xdist, 0.5)
+
+            if kie_model:
+                annotations = copy.deepcopy(img_e2e_res['result'])
+                # Customized for kie_dataset, which
+                # assumes that boxes are represented by only 4 points
+                for i, ann in enumerate(annotations):
+                    min_x = min(ann['box'][::2])
+                    min_y = min(ann['box'][1::2])
+                    max_x = max(ann['box'][::2])
+                    max_y = max(ann['box'][1::2])
+                    annotations[i]['box'] = [
+                        min_x, min_y, max_x, min_y, max_x, max_y, min_x, max_y
+                    ]
+                ann_info = kie_dataset._parse_anno_info(annotations)
+                kie_result, data = model_inference(
+                    kie_model,
+                    arr,
+                    ann=ann_info,
+                    return_data=True,
+                    batch_mode=self.args.batch_mode)
+                # visualize KIE results
+                self.visualize_kie_output(
+                    kie_model,
+                    data,
+                    kie_result,
+                    out_file=out_file,
+                    show=self.args.imshow)
+                gt_bboxes = data['gt_bboxes'].data.numpy().tolist()
+                labels = self.generate_kie_labels(kie_result, gt_bboxes,
+                                                  kie_model.class_list)
+                for i in range(len(gt_bboxes)):
+                    img_e2e_res['result'][i]['label'] = labels[i][0]
+                    img_e2e_res['result'][i]['label_score'] = labels[i][1]
+
+            end2end_res.append(img_e2e_res)
+        return end2end_res
+
+    # Separate det/recog inference pipeline
+    def single_inference(self, model, arrays, batch_mode, batch_size):
+        result = []
+        if batch_mode:
+            if batch_size == 0:
+                result = model_inference(model, arrays, batch_mode=True)
+            else:
+                n = batch_size
+                arr_chunks = [
+                    arrays[i:i + n] for i in range(0, len(arrays), n)
+                ]
+                for chunk in arr_chunks:
+                    result.extend(
+                        model_inference(model, chunk, batch_mode=True))
+        else:
+            for arr in arrays:
+                result.append(model_inference(model, arr, batch_mode=False))
+        return result
+
+    # Arguments pre-processing function
+    def _args_processing(self, args):
+        # Check if the input is a list/tuple that
+        # contains only np arrays or strings
+        if isinstance(args.img, (list, tuple)):
+            img_list = args.img
+            if not all([isinstance(x, (np.ndarray, str)) for x in args.img]):
+                raise AssertionError('Images must be strings or numpy arrays')
+
+        # Create a list of the images
+        if isinstance(args.img, str):
+            img_path = Path(args.img)
+            if img_path.is_dir():
+                img_list = [str(x) for x in img_path.glob('*')]
+            else:
+                img_list = [str(img_path)]
+        elif isinstance(args.img, np.ndarray):
+            img_list = [args.img]
+
+        # Read all image(s) in advance to reduce wasted time
+        # re-reading the images for vizualisation output
+        args.arrays = [mmcv.imread(x) for x in img_list]
+
+        # Create a list of filenames (used for output images and result files)
+        if isinstance(img_list[0], str):
+            args.filenames = [str(Path(x).stem) for x in img_list]
+        else:
+            args.filenames = [str(x) for x in range(len(img_list))]
+
+        # If given an output argument, create a list of output image filenames
+        num_res = len(img_list)
+        if args.output:
+            output_path = Path(args.output)
+            if output_path.is_dir():
+                args.output = [
+                    str(output_path / f'out_{x}.png') for x in args.filenames
+                ]
+            else:
+                args.output = [str(args.output)]
+                if args.batch_mode:
+                    raise AssertionError('Output of multiple images inference'
+                                         ' must be a directory')
+        else:
+            args.output = [None] * num_res
+
+        # If given an export argument, create a list of
+        # result filenames for each image
+        if args.export:
+            export_path = Path(args.export)
+            args.export = [
+                str(export_path / f'out_{x}.{args.export_format}')
+                for x in args.filenames
+            ]
+        else:
+            args.export = [None] * num_res
+
+        return args
+
+
+# Create an inference pipeline with parsed arguments
+def main():
+    args = parse_args()
+    ocr = MMOCR(**vars(args))
+    ocr.readtext(**vars(args))
+
 
 if __name__ == '__main__':
     main()