diff --git a/core/src/grpc/README.md b/core/src/grpc/README.md
index 44c4e9084136532d08a86a80ba0871458922dc5f..6a3fe1157caff720570eea422d169ccd7473de1f 100644
--- a/core/src/grpc/README.md
+++ b/core/src/grpc/README.md
@@ -1,4 +1,4 @@
-We manually change two APIs in "milvus.pd.h":
+We manually change two APIs in "milvus.pb.h":
     add_vector_data()
     add_row_id_array()
     add_ids()