I have been U.S.A as a visiting scholar with J1 Visa for nearly 3 years. My USA colledge give me living compensation by check, but no social seculty, medicare and other benefit.

In the 2010(4th year in US), I will transfer a staff position in USA colledge with J1. Do I qualify the US-China tax treaty now?

Thanks.

Once you enter the fourth year on your J-1 visa, you will be considered to be a resident alien for tax purposes.

This makes you liable for ALL taxes (federal and state income taxes plus FICA taxes) that are paid by U.S. citizens.