diff --git a/README.md b/README.md
index 0b73beda5..3c835e819 100644
--- a/README.md
+++ b/README.md
@@ -66,7 +66,7 @@ This project is released under the [Apache 2.0 license](LICENSE).
 
 ## Changelog
 
-v0.20.2 was released in 12/15/2021.
+v0.21.0 was released in 1/29/2022.
 Please refer to [changelog.md](docs/en/changelog.md) for details and release history.
 
 ## Benchmark and model zoo
diff --git a/README_zh-CN.md b/README_zh-CN.md
index ebcdd4504..3393badf0 100644
--- a/README_zh-CN.md
+++ b/README_zh-CN.md
@@ -65,7 +65,7 @@ MMSegmentation 是一个基于 PyTorch 的语义分割开源工具箱。它是 O
 
 ## 更新日志
 
-最新的月度版本 v0.20.2 在 2021.12.15 发布。
+最新的月度版本 v0.21.0 在 2022.1.29 发布。
 如果想了解更多版本更新细节和历史信息，请阅读[更新日志](docs/en/changelog.md)。
 
 ## 基准测试和模型库
diff --git a/docker/serve/Dockerfile b/docker/serve/Dockerfile
index 1ef44abd2..31a5d443f 100644
--- a/docker/serve/Dockerfile
+++ b/docker/serve/Dockerfile
@@ -3,8 +3,8 @@ ARG CUDA="10.1"
 ARG CUDNN="7"
 FROM pytorch/pytorch:${PYTORCH}-cuda${CUDA}-cudnn${CUDNN}-devel
 
-ARG MMCV="1.3.13"
-ARG MMSEG="0.20.0"
+ARG MMCV="1.4.4"
+ARG MMSEG="0.21.0"
 
 ENV PYTHONUNBUFFERED TRUE
 
diff --git a/docs/en/changelog.md b/docs/en/changelog.md
index a615a03c6..3de3bbdc3 100644
--- a/docs/en/changelog.md
+++ b/docs/en/changelog.md
@@ -1,6 +1,44 @@
 ## Changelog
 
 
+### V0.21 (1/29/2022)
+
+**Highlights**
+
+- Officially Support CPUs training and inference, please use the latest MMCV (1.4.4) to try it out.
+- Support Segmenter: Transformer for Semantic Segmentation (ICCV'2021).
+- Support ISPRS Potsdam and Vaihingen Dataset.
+- Add Mosaic transform and `MultiImageMixDataset` class in `dataset_wrappers`.
+
+**New Features**
+
+- Support Segmenter: Transformer for Semantic Segmentation (ICCV'2021) ([#955](https://github.com/open-mmlab/mmsegmentation/pull/955))
+- Support ISPRS Potsdam and Vaihingen Dataset ([#1097](https://github.com/open-mmlab/mmsegmentation/pull/1097), [#1171](https://github.com/open-mmlab/mmsegmentation/pull/1171))
+- Add segformer‘s benchmark on cityscapes ([#1155](https://github.com/open-mmlab/mmsegmentation/pull/1155))
+- Add auto resume ([#1172](https://github.com/open-mmlab/mmsegmentation/pull/1172))
+- Add Mosaic transform and `MultiImageMixDataset` class in `dataset_wrappers` ([#1093](https://github.com/open-mmlab/mmsegmentation/pull/1093), [#1105](https://github.com/open-mmlab/mmsegmentation/pull/1105))
+- Add log collector ([#1175](https://github.com/open-mmlab/mmsegmentation/pull/1175))
+
+**Improvements**
+
+- New-style CPU training and inference ([#1251](https://github.com/open-mmlab/mmsegmentation/pull/1251))
+- Add UNet benchmark with multiple losses supervision ([#1143](https://github.com/open-mmlab/mmsegmentation/pull/1143))
+
+**Bug Fixes**
+
+- Fix the model statistics in doc for readthedoc ([#1153](https://github.com/open-mmlab/mmsegmentation/pull/1153))
+- Set random seed for `palette` if not given ([#1152](https://github.com/open-mmlab/mmsegmentation/pull/1152))
+- Add `COCOStuffDataset` in `class_names.py` ([#1222](https://github.com/open-mmlab/mmsegmentation/pull/1222))
+- Fix bug in non-distributed multi-gpu training/testing ([#1247](https://github.com/open-mmlab/mmsegmentation/pull/1247))
+- Delete unnecessary lines of STDCHead ([#1231](https://github.com/open-mmlab/mmsegmentation/pull/1231))
+
+**Contributors**
+
+- @jbwang1997 made their first contribution in https://github.com/open-mmlab/mmsegmentation/pull/1152
+- @BeaverCC made their first contribution in https://github.com/open-mmlab/mmsegmentation/pull/1206
+- @Echo-minn made their first contribution in https://github.com/open-mmlab/mmsegmentation/pull/1214
+- @rstrudel made their first contribution in https://github.com/open-mmlab/mmsegmentation/pull/955
+
 ### V0.20.2 (12/15/2021)
 
 **Bug Fixes**
@@ -53,7 +91,7 @@
 **Bug Fixes**
 
 - Fix incorrectly loading init_cfg or pretrained models of several transformer models ([#999](https://github.com/open-mmlab/mmsegmentation/pull/999), [#1069](https://github.com/open-mmlab/mmsegmentation/pull/1069), [#1102](https://github.com/open-mmlab/mmsegmentation/pull/1102))
-- Fix EfficientMultiheadAttention in SegFormer ([#1003](https://github.com/open-mmlab/mmsegmentation/pull/1037))
+- Fix EfficientMultiheadAttention in SegFormer ([#1037](https://github.com/open-mmlab/mmsegmentation/pull/1037))
 - Remove `fp16` folder in `configs` ([#1031](https://github.com/open-mmlab/mmsegmentation/pull/1031))
 - Fix several typos in .yml file (Dice Metric [#1041](https://github.com/open-mmlab/mmsegmentation/pull/1041), ADE20K dataset [#1120](https://github.com/open-mmlab/mmsegmentation/pull/1120), Training Memory (GB) [#1083](https://github.com/open-mmlab/mmsegmentation/pull/1083))
 - Fix test error when using `--show-dir` ([#1091](https://github.com/open-mmlab/mmsegmentation/pull/1091))
diff --git a/docs/en/get_started.md b/docs/en/get_started.md
index 032d61af9..bd7745626 100644
--- a/docs/en/get_started.md
+++ b/docs/en/get_started.md
@@ -9,25 +9,26 @@
 
 The compatible MMSegmentation and MMCV versions are as below. Please install the correct version of MMCV to avoid installation issues.
 
-| MMSegmentation version |    MMCV version     |
-|:-------------------:|:-------------------:|
-| master              | mmcv-full>=1.3.13, <1.5.0 |
-| 0.20.0              | mmcv-full>=1.3.13, <1.5.0 |
-| 0.19.0              | mmcv-full>=1.3.13, <1.4.0 |
-| 0.18.0              | mmcv-full>=1.3.13, <1.4.0 |
-| 0.17.0              | mmcv-full>=1.3.7, <1.4.0 |
-| 0.16.0              | mmcv-full>=1.3.7, <1.4.0 |
-| 0.15.0              | mmcv-full>=1.3.7, <1.4.0 |
-| 0.14.1              | mmcv-full>=1.3.7, <1.4.0 |
-| 0.14.0              | mmcv-full>=1.3.1, <1.3.2 |
-| 0.13.0              | mmcv-full>=1.3.1, <1.3.2 |
-| 0.12.0              | mmcv-full>=1.1.4, <1.3.2 |
-| 0.11.0              | mmcv-full>=1.1.4, <1.3.0 |
-| 0.10.0              | mmcv-full>=1.1.4, <1.3.0 |
-| 0.9.0               | mmcv-full>=1.1.4, <1.3.0 |
-| 0.8.0               | mmcv-full>=1.1.4, <1.2.0 |
-| 0.7.0               | mmcv-full>=1.1.2, <1.2.0 |
-| 0.6.0               | mmcv-full>=1.1.2, <1.2.0 |
+| MMSegmentation version |        MMCV version        |
+|:----------------------:|:--------------------------:|
+|         master         |  mmcv-full>=1.4.4, <1.5.0  |
+|         0.21.0         |  mmcv-full>=1.4.4, <1.5.0  |
+|         0.20.0         | mmcv-full>=1.3.13, <1.5.0  |
+|         0.19.0         | mmcv-full>=1.3.13, <1.3.17 |
+|         0.18.0         | mmcv-full>=1.3.13, <1.3.17 |
+|         0.17.0         | mmcv-full>=1.3.7, <1.3.17  |
+|         0.16.0         | mmcv-full>=1.3.7, <1.3.17  |
+|         0.15.0         | mmcv-full>=1.3.7, <1.3.17  |
+|         0.14.1         | mmcv-full>=1.3.7, <1.3.17  |
+|         0.14.0         |  mmcv-full>=1.3.1, <1.3.2  |
+|         0.13.0         |  mmcv-full>=1.3.1, <1.3.2  |
+|         0.12.0         |  mmcv-full>=1.1.4, <1.3.2  |
+|         0.11.0         |  mmcv-full>=1.1.4, <1.3.0  |
+|         0.10.0         |  mmcv-full>=1.1.4, <1.3.0  |
+|         0.9.0          |  mmcv-full>=1.1.4, <1.3.0  |
+|         0.8.0          |  mmcv-full>=1.1.4, <1.2.0  |
+|         0.7.0          |  mmcv-full>=1.1.2, <1.2.0  |
+|         0.6.0          |  mmcv-full>=1.1.2, <1.2.0  |
 
 :::{note}
 You need to run `pip uninstall mmcv` first if you have mmcv installed.
diff --git a/docs/zh_cn/get_started.md b/docs/zh_cn/get_started.md
index 142206d22..372bab92d 100644
--- a/docs/zh_cn/get_started.md
+++ b/docs/zh_cn/get_started.md
@@ -9,25 +9,26 @@
 
 可编译的 MMSegmentation 和 MMCV 版本如下所示，请对照对应版本安装以避免安装问题。
 
-| MMSegmentation 版本 |    MMCV 版本     |
-|:-------------------:|:-------------------:|
-| master              | mmcv-full>=1.3.13, <1.5.0 |
-| 0.20.0              | mmcv-full>=1.3.13, <1.5.0 |
-| 0.19.0              | mmcv-full>=1.3.13, <1.4.0 |
-| 0.18.0              | mmcv-full>=1.3.13, <1.4.0 |
-| 0.17.0              | mmcv-full>=1.3.7, <1.4.0 |
-| 0.16.0              | mmcv-full>=1.3.7, <1.4.0 |
-| 0.15.0              | mmcv-full>=1.3.7, <1.4.0 |
-| 0.14.1              | mmcv-full>=1.3.7, <1.4.0 |
-| 0.14.0              | mmcv-full>=1.3.1, <1.4.0 |
-| 0.13.0              | mmcv-full>=1.3.1, <1.4.0 |
-| 0.12.0              | mmcv-full>=1.1.4, <1.4.0 |
-| 0.11.0              | mmcv-full>=1.1.4, <1.3.0 |
-| 0.10.0              | mmcv-full>=1.1.4, <1.3.0 |
-| 0.9.0               | mmcv-full>=1.1.4, <1.3.0 |
-| 0.8.0               | mmcv-full>=1.1.4, <1.2.0 |
-| 0.7.0               | mmcv-full>=1.1.2, <1.2.0 |
-| 0.6.0               | mmcv-full>=1.1.2, <1.2.0 |
+| MMSegmentation 版本 |          MMCV 版本           |
+|:-----------------:|:--------------------------:|
+|      master       |  mmcv-full>=1.4.4, <1.5.0  |
+|      0.21.0       |  mmcv-full>=1.4.4, <1.5.0  |
+|      0.20.0       | mmcv-full>=1.3.13, <1.5.0  |
+|      0.19.0       | mmcv-full>=1.3.13, <1.3.17 |
+|      0.18.0       | mmcv-full>=1.3.13, <1.3.17 |
+|      0.17.0       | mmcv-full>=1.3.7, <1.3.17  |
+|      0.16.0       | mmcv-full>=1.3.7, <1.3.17  |
+|      0.15.0       | mmcv-full>=1.3.7, <1.3.17  |
+|      0.14.1       | mmcv-full>=1.3.7, <1.3.17  |
+|      0.14.0       |  mmcv-full>=1.3.1, <1.3.2  |
+|      0.13.0       |  mmcv-full>=1.3.1, <1.3.2  |
+|      0.12.0       |  mmcv-full>=1.1.4, <1.3.2  |
+|      0.11.0       |  mmcv-full>=1.1.4, <1.3.0  |
+|      0.10.0       |  mmcv-full>=1.1.4, <1.3.0  |
+|       0.9.0       |  mmcv-full>=1.1.4, <1.3.0  |
+|       0.8.0       |  mmcv-full>=1.1.4, <1.2.0  |
+|       0.7.0       |  mmcv-full>=1.1.2, <1.2.0  |
+|       0.6.0       |  mmcv-full>=1.1.2, <1.2.0  |
 
 注意: 如果您已经安装好 mmcv， 您首先需要运行 `pip uninstall mmcv`。
 如果 mmcv 和 mmcv-full 同时被安装，会报错 `ModuleNotFoundError`。
diff --git a/mmseg/version.py b/mmseg/version.py
index c5db4851f..19ddd59f9 100644
--- a/mmseg/version.py
+++ b/mmseg/version.py
@@ -1,6 +1,6 @@
 # Copyright (c) Open-MMLab. All rights reserved.
 
-__version__ = '0.20.2'
+__version__ = '0.21.0'
 
 
 def parse_version_info(version_str):