diff --git a/optimistic-transaction.md b/optimistic-transaction.md
index ac795e21f60c..372be5149f6b 100644
--- a/optimistic-transaction.md
+++ b/optimistic-transaction.md
@@ -30,7 +30,7 @@ sequenceDiagram
     client->>TiDB: begin
     TiDB->>PD: get ts as start_ts
 
-    loop excute SQL
+    loop execute SQL
         alt do read
             TiDB->>PD: get region from PD or cache
             TiDB->>TiKV: get data from TiKV or cache with start_ts