diff --git a/doc/design/model_format.md b/doc/design/model_format.md
index 118f2a88880e3d4acb07efc89ad463985fb7df0a..a1c086775acbee6d05ebf69d7de9c7c3ac2cd36e 100644
--- a/doc/design/model_format.md
+++ b/doc/design/model_format.md
@@ -34,5 +34,5 @@ The table below shows a tensor's byte view in detail. Note that all the signed v
 ## Summary
 
 - We introduce a model format.
-- The model represented by its forward-pass computation procedure saved in a **ProgramDesc** protobuf message.
+- The model represented by its forward-pass computation procedure is saved in a **ProgramDesc** protobuf message.
 - A bunch of specified format binary tensors describe the **parameters**.