Can you please tell us if this is Dynamo for Revit or DynamoSandbox? What version of Windows? If it is D4R what version of Revit are you running, and what is the /language country code set to (this is in the Revit command line)? What are your localisation settings as shown in the Windows Control Panel? Do you have Dynamo 1.3 installed, and if so, does it display Chinese characters correctly?
If we use either the CHT or CHS language code with Revit the Dynamo Start page displays correctly in Chinese.
One thing to check: you may have an incorrect installation of Dynamo, could you please check in the Control Panel for older versions of Dynamo?