diff --git a/README.md b/README.md
index 12bbfa7..61c8791 100644
--- a/README.md
+++ b/README.md
@@ -1,19 +1,24 @@
 # 简介
 
-使用图像直观展示 `golang` 包依赖关系
+> 使用图像直观展示 `golang` 包依赖关系
 
 # 安装
 
-`go get github.com/iNevd/graphpkg`
+> `go get github.com/iNevd/graphpkg`
+
+# 依赖
+
+> 依赖[graphviz](http://www.graphviz.org/)
 
 # 使用
 
-`graphpkg [package1 package2...]`
+> `graphpkg [package1 package2...]`
 
-`graphpkg net`
+> `graphpkg net`
 
 # 例子
 
-`graphpkg os` 结果输出如图
+> `graphpkg os` 结果输出如图
 
 ![time](https://user-images.githubusercontent.com/9940894/58329957-6e13ca00-7e68-11e9-8243-49ea965b4dd3.jpg)
+