diff --git a/README.md b/README.md
index b0e014d..8a52b02 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,33 @@
 # NTV03_MessageBoxTimeout
-NTAPI自动消失的消息框视频源代码
+NTAPI自动消失的消息框视频源代码，用于演示未公开的API
+ - MessageBoxTimeoutA
+ - MessageBoxTimeoutW
+
+## 关于MessageBoxTimeoutA
+
+### 函数原型
+```c++
+int MessageBoxTimeoutA(IN HWND hWnd, IN LPCSTR lpText, IN LPCSTR lpCaption, IN UINT uType, IN WORD wLanguageId, IN DWORD dwMilliseconds);
+```
+
+### 所在DLL
+ - user32.dll
+
+## 关于MessageBoxTimeoutW
+
+### 函数原型
+```c++
+int MessageBoxTimeoutW(IN HWND hWnd, IN LPCWSTR lpText, IN LPCWSTR lpCaption, IN UINT uType, IN WORD wLanguageId, IN DWORD dwMilliseconds);
+```
+
+### 所在DLL
+ - user32.dll
+ 
+ ## 兼容不同字符集所使用的宏定义
+ ```
+#ifdef _UNICODE
+#define MessageBoxTimeout MessageBoxTimeoutW
+#else
+#define MessageBoxTimeout MessageBoxTimeoutA
+#endif
+ ```