There are many applicants from China. Most admitted applicants are from countries other than the United States. Most applicants are from top universities in their home countries, such as Peking University in Qinghua University in China. If you are at a top university, you can find others who are applying to Brown and other good U.S. schools and you can get advice from them. If not, perhaps you can find such advice posted by similar students on the internet. I’m not able to give guidance to the hundreds of prospective applicants we have, but if you have not studied at a very strong university or if you do nto yet have a very strong record in mathematics, your chance of admission to a top U.S. graduate program is probably very low unless you first get an MA degree first at a good university in China.