Question

It does not affect JSON deserialization. Any one can explain it?

Answer 1

The documentation states the following:

If you apply ScriptIgnoreAttribute to a public property or public field of a class, then JavaScriptSerializer ignores, or skips, the member when serializing an instance of the class to JavaScript Object Notation (JSON) format.

I take it the same holds for the JSON serializer. The documentation does not state anything concerning deserialization.

I believe the idea is that when you don’t serialize a property, deserialization does not matter because the property simply isn’t there in the to be deserialized data.