I am using import and export values between US and China, and  EU and China,1989 to 2006
for my projects from SITC Rev.3, based on 3 digital calculation.
However, there are some values are not avaiable, such as, 011: Meat of bovine animals,
fresh, chilled or frozen, there are no value for this sector. I am wondering that means
no trade betwenn those countries, or means no information provided.

It can be both.  No information usually means no trade however it can also be confidential data.