diff --git a/SUMMARY.md b/SUMMARY.md
index 3c53119..47d886e 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -3,6 +3,6 @@
 * [前言](README.md)
 * [第一个Python程序](di-yi-ge-python-cheng-xu.md)
   * [一、Python 简介](yi-3001-python-jian-jie.md)
-* [二、Python 的安装 ](er-3001-python-de-an-zhuang.md)
-* [三、第一个 Python 程序 Hello Python](san-3001-di-yi-ge-python-cheng-xu-hello-python.md)
+  * [二、Python 的安装 ](er-3001-python-de-an-zhuang.md)
+  * [三、第一个 Python 程序 Hello Python](san-3001-di-yi-ge-python-cheng-xu-hello-python.md)