Abstract: The alkali-feldspar granite of the study area located 20km south of the superlarge Oyu Tolgoi Cu-Au deposit. The tecton-ic setting of the study area belongs to Paleozoic island arc zone of Gobi-Tianshan controlled by intersection of the near-latitudinal fault and an oblique transverse fault on the south margin of Siberian plate. A sample was collected from Onealkali-feldspar granite, and CL characteristics of zircons suggest magmatic origin. LA-ICP-MS U-Pb dating of zircon from the sample shows that the em-placing age is 286.0± 0.91Ma (MSWD=1.4), belonging to Permian period. The study area is characterized by multiperiodic diagenesis and mineralization. The isotope age provides not only the direct evidence for the multiperiodic magmatic activities but also the pros-pecting direction for the study area.