diff --git a/Assets/fork_button.png b/Assets/fork_button.png
new file mode 100644
index 0000000..8fda151
Binary files /dev/null and b/Assets/fork_button.png differ
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 19de984..323a8e3 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -5,7 +5,7 @@
 
 1. 点击 `fork` 按钮：
 
-    ![fork](http://oi58.tinypic.com/jj2trm.jpg)
+    ![fork](./Assets/fork_button.png)
 
 2. 通过如下命令从你的 Github 帐号 `clone` 库：