diff --git a/README.md b/README.md
index 807e3eb..17d849b 100644
--- a/README.md
+++ b/README.md
@@ -109,6 +109,8 @@ subgraph sysu-compiler
 direction TB
 subgraph frontend
 direction LR
+preprocessor--Code-->grammar
+grammar--JsonAST-->generator
 preprocessor--Code-->lexer
 lexer--TokenFlow-->parser
 parser--JsonAST-->generator