This paper quantitatively estimates the effect of FDI on China's technology innovation(reflected by the number of patent applications)using a large sample of panel data including 29 areas from 1995 to 2003.It is shown that FDI will benefit China's technology innovation,if it passes the "human capital threshold".FDI will have the different effect on the number of three types of patent application.This has the greatest effect on external design,less on utility model,and least on invention.Further study reveals that this effect will have remarkably regional characteristic: strong and positive in eastern China,moderate in the middle of China,almost none in western China.