http://www.irs.gov/pub/irs-trty/china.pdf
ARTICLE 19
(Teachers, Professors and Researchers)
An individual who is, or immediately before visiting a Contracting State was, a resident of the other contracting
State and is temporarily present in the first-mentioned Contracting State for the primary purpose of teaching, giving
lectures or conducting research at a university, college, school or other accredited educational institution or scientific research institution in the first mentioned Contracting State shall be exempt from tax in the first mentioned Contracting State for a period not exceeding three years in the aggregate in respect of remuneration for such teaching, lectures or research.