LA-ICP MS zircon U-Pb dating results of granites from Sawuer Mountains in North Xinjiang,NW China,are reported based on 1∶50 000 regional geologic surveys.Zircon U-Pb dating shows that the granitoids have magmatic crystallization age of 320±2 Ma.In addition,zircons with ages of 341~358 Ma could be subdivided into two groups,i.e.,Group 1 with a weighted mean age of 342±3 Ma and Group 2 with a weighted mean age of 354±2 Ma.The petrology and geochemistry of granitoids from Sawuer Mountains suggest their mixed origin.The granite from Sawuer Mountains occurred in an extensional setting,most probably related to post-orogenic processes during the closure of the Peo-Asian Ocean;namely,represent the tectonic setting shifted from compress to post-collisional setting. LA-ICP MS zircon U-Pb dating results of the granites from Sawuer Mountains in North Xinjiang, NW China, are reported based on 1:50 000 regional geologic surveys. Zircon U-Pb dating shows that the granitoids have magmatic crystallization age of 320 ± 2 Ma. Addition, zircons with ages of 341-358 Ma could be subdivided into two groups, ie, Group 1 with a weighted mean age of 342 ± 3 Ma and Group 2 with a weighted mean age of 354 ± 2 Ma. petrology and geochemistry of granitoids from Sawuer Mountains suggest their mixed origin. The granite from Sawuer Mountains occurred in an extensional setting, most probably related to post-orogenic processes during the closure of the Peo-Asian Ocean; namely, represent the tectonic setting shifted from compress to post-collisional setting.