diff --git a/sync_diff_inspector/README.md b/sync_diff_inspector/README.md
index 87dc46a10..cd07ffd7c 100644
--- a/sync_diff_inspector/README.md
+++ b/sync_diff_inspector/README.md
@@ -1,5 +1,7 @@
 # sync-diff-inspector
 
+Deprecated: The code has been moved to https://github.com/pingcap/tiflow/tree/master/sync_diff_inspector
+
 sync-diff-inspector is a tool for comparing two database's data.
 
 ## How to use