It is absolutely unnecessary to bring a gift when invited to dinner， but if you want to do so it should be a small， inexpensive item.
You might bring some sweets， or some， small toys for the children， or something from China. Here are some suggestions： a papercut is a lovely gift（one is fine， not a whole package）；if you want to make it even fancier， you can buy a very inexpensive frame in the local five-and-ten and frame it. Chinese tea is a wonderful gift； it's true that Chinese tea is available in the States， but the fact that you chose it and brought it with you from China makes it very special. Chinese book marks are very lovely gifts， and if you want to buy a set of Chinese paintings which you admire， you might give one of them as a gift. One of the nicest things you can do is to cook some typical Chinese dish and bring it with you.
Again， however， a gift is not necessary， and if you come with a group of scholars or students one small token（象徵性的） gift from all of you （rather than each of you） is entirely satisfactory.