diff --git a/README.md b/README.md
index a5e5416..7361d5e 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,5 @@
+>  设计文档为PLAN.md
+
 LevelDB is a fast key-value storage library written at Google that provides an ordered mapping from string keys to string values.
 
 > **This repository is receiving very limited maintenance. We will only review the following types of changes.**