diff --git a/doc/IOSDocument.md b/doc/IOSDocument.md
index d701457..90447cc 100644
--- a/doc/IOSDocument.md
+++ b/doc/IOSDocument.md
@@ -25,9 +25,9 @@ V
 
 2）配置URL-schema  
 Xcode 5: Open your application settings then select the Info tab. In the URL Types section click the plus sign. Enter vk+APP_ID (e.g. vk1234567) to the Identifier and URL Schemes fields.  
-![](images/vk1.png)     
+![](images/vk1.jpg)     
 Xcode 4: Open your Info.plist then add a new row URL Types. Set the URL identifier to vk+APP_ID
-![](images/vk2.png)     
+![](images/vk2.jpg)     
 ## 5、在工程里添加SDK登录代码  
 
 	[LetsGameAPI instance].appId = @"100"; // 设置appId