diff --git a/README-cn.md b/README-cn.md
index 903ab1d..2b937de 100755
--- a/README-cn.md
+++ b/README-cn.md
@@ -301,7 +301,8 @@ ptrFrame.setPtrHandler(new PtrHandler() {
 
 *  长按LongPressed, `setInterceptEventWhileWorking()`
 
-
+# 项目原理及一些方法的解释
+*  http://www.liaohuqiu.net/cn/posts/the-pull-to-refresh-in-my-eyes/
 # 联系方式和问题建议
 
 * 微博: http://weibo.com/liaohuqiu