Zircons from granodiorite and biotite granite in the Yeniutan granitic intrusion in the western North Qilian Mountains ylelded a weighted mean 206PH/apparent age of 460±3Ma, suggesting that the intrusion originated during the late stage of plate subuotion Its related Ta’ergou and Xiaoliugou deposits are two of the few large tungsten deposits formed in the plate subduction environment in the world. The U-Pb dating of the zircons from the biotite granite gave a discordant lower intercept age of 183±4 Ma, which implies that the Yanshanian event was probably superimposed on the North Qilian region.