diff --git a/NEWS.md b/NEWS.md
index 71b1aead18..0c0c6d2d63 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,8 +1,12 @@
 tag next
 --------------------------------
+
+tag k0.3.1
+--------------------------------
 player: key-value options API
 player: remove ijkutil
 build: support cygwin
+ios: optimize performance of VideoToolbox.
 
 tag k0.3.0
 --------------------------------
diff --git a/README.md b/README.md
index 07d54819e3..12ab107e24 100644
--- a/README.md
+++ b/README.md
@@ -94,7 +94,7 @@ sudo dpkg-reconfigure dash
 ```
 git clone https://github.com/Bilibili/ijkplayer.git ijkplayer-android
 cd ijkplayer-android
-git checkout -B latest k0.3.0
+git checkout -B latest k0.3.1
 
 ./init-android.sh
 
@@ -130,7 +130,7 @@ cd ..
 ```
 git clone https://github.com/Bilibili/ijkplayer.git ijkplayer-ios
 cd ijkplayer-ios
-git checkout -B latest k0.3.0
+git checkout -B latest k0.3.1
 
 ./init-ios.sh
 
@@ -150,12 +150,6 @@ cd ios
 - 请尽量在 github 上公开讨论[技术问题](https://github.com/bilibili/ijkplayer/issues)，不要以邮件方式私下询问，恕不一一回复。
 
 
-### Links
-- [FFmpeg_b4a](http://www.basic4ppc.com/android/forum/threads/ffmpeg_b4a-a-ffmpeg-library-for-b4a-decoding-streaming.44476/)
-- 中文
- - [ijkplayer学习系列之环境搭建 2013-11-23](http://blog.csdn.net/nfer_zhuang/article/details/16905755)
- - [Ubuntu 14.04 下编译 ijkplayer Android 2014-08-01](http://xqq.0ginr.com/ijkplayer-build/#more-134)
-
 ### License
 
 ```
diff --git a/android/ijkplayer/gradle.properties b/android/ijkplayer/gradle.properties
index 1d31813137..cb853f9af4 100644
--- a/android/ijkplayer/gradle.properties
+++ b/android/ijkplayer/gradle.properties
@@ -17,8 +17,8 @@
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
 # org.gradle.parallel=true
 
-VERSION_NAME=0.3.0-dev001
-VERSION_CODE=300001
+VERSION_NAME=0.3.1-dev001
+VERSION_CODE=301000
 GROUP=tv.danmaku.ijk.media
 
 POM_DESCRIPTION=Video player based on FFmpeg n2.7
@@ -30,4 +30,4 @@ POM_LICENCE_NAME=LGPLv2.1 or later
 POM_LICENCE_URL=https://www.gnu.org/licenses/lgpl-2.1.html
 POM_LICENCE_DIST=repo
 POM_DEVELOPER_ID=bbcallen
-POM_DEVELOPER_NAME=Zhang Rui
\ No newline at end of file
+POM_DEVELOPER_NAME=Zhang Rui
diff --git a/android/ijkplayer/sample/build.gradle b/android/ijkplayer/sample/build.gradle
index a501f19dd2..8e8b90329b 100644
--- a/android/ijkplayer/sample/build.gradle
+++ b/android/ijkplayer/sample/build.gradle
@@ -11,8 +11,8 @@ android {
         applicationId "tv.danmaku.ijk.media.sample"
         minSdkVersion 9
         targetSdkVersion 22
-        versionCode 300000
-        versionName "0.3.0"
+        versionCode 301000
+        versionName "0.3.1"
     }
     buildTypes {
         release {
@@ -31,4 +31,4 @@ dependencies {
     compile project(':player-armv5')
     // need API-21
     // compile project(':player-arm64')
-}
\ No newline at end of file
+}
diff --git a/ios/IJKMediaDemo/IJKMediaDemo/IJKMediaDemo-Info.plist b/ios/IJKMediaDemo/IJKMediaDemo/IJKMediaDemo-Info.plist
index 960cb28e36..5d35a7798b 100644
--- a/ios/IJKMediaDemo/IJKMediaDemo/IJKMediaDemo-Info.plist
+++ b/ios/IJKMediaDemo/IJKMediaDemo/IJKMediaDemo-Info.plist
@@ -17,11 +17,11 @@
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>0.1.2</string>
+	<string>0.3.1</string>
 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>
-	<string>102</string>
+	<string>301</string>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
 	<key>UIFileSharingEnabled</key>