diff --git a/docs/design_docs/datanode_flowgraph_recovery_design_0604_2021.md b/docs/design_docs/datanode_flowgraph_recovery_design_0604_2021.md
index 372875f0aa..960cc59b91 100644
--- a/docs/design_docs/datanode_flowgraph_recovery_design_0604_2021.md
+++ b/docs/design_docs/datanode_flowgraph_recovery_design_0604_2021.md
@@ -42,7 +42,7 @@ Whether save successfully:
 
 1. We need all positions of all segments in this vchannel `p1, p2, ... pn`.
 
-A design of WatchDmChannelReq
+Proto design for WatchDmChannelReq:
 
 ```proto
 message VchannelInfo {