From November 17, 2014, the  Chinese Embassy in Korea accept 10-year multiple entries visa application for tourist(L)/ business(M)/ short-term vsit to the relatives (Q2)/ private matters(S2) purposes and 5-year multiple entries visa application for study(X1) purpose for US passport holder. The requirements are the same as before, the passport submitted should be valid for at least 1 year. 

Chinese Visa Application Service Center

17 November 2014