diff --git a/UPGRADING.md b/UPGRADING.md
index db83da06..7e2c6ef6 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -1,6 +1,14 @@
 cos-php-sdk-v5 Upgrade Guide
 ====================
 
+2.0.9 to 2.1.0
+----------
+- `upload` support upload with multithread
+- Add `retry` params for interface retry
+- Support add customer header
+- Signature will restrict part of the header and all parameters
+- fix `listBuckets` with `doamin`
+
 2.0.8 to 2.0.9
 ----------
 - Fix bug of `listObjectVersions`
diff --git a/src/Qcloud/Cos/Client.php b/src/Qcloud/Cos/Client.php
index 24ec6dfb..ff0b4b22 100644
--- a/src/Qcloud/Cos/Client.php
+++ b/src/Qcloud/Cos/Client.php
@@ -18,7 +18,7 @@
 use GuzzleHttp\Psr7;
 
 class Client extends GuzzleClient {
-    const VERSION = '2.0.9';
+    const VERSION = '2.1.0';
 
     public $httpClient;