I do not think you need to pay any of the income tax if you are doing research or teaching in US. The tax treaty between US and China is quite generous to these types of jobs. You do need to pay medical tax and social security tax though.

Check http://www.irs.gov/pub/irs-trty/china.pdf article 19

and publication 519 http://www.irs.gov/pub/irs-pdf/p519.pdf page 49 about teachers, professors and researchers.

[此贴子已经被作者于2006-3-31 21:39:26编辑过]