Dear Xiaodong,
I am sorry you are having trouble in making friends.However,the situation is easy to change if you take my advice.Here are some tips to help you.
First,why not take an active part in you classmates'talking and show you ideas? If you do so,your classmates will understand you more.Secondly,you should be polite to your classmates.That way,they will have a good feeling for you.Thirdly,it would be a good idea if you can help your classmates solve some problems in or out of studying.By doing this,I think they will like to make friends with you.
I hope you will find these ideas uesful.Good luck to you!
Yous,
Rose