The Yazigou polymetallic deposit, discovered recently by the Qinghai Geological Survey in the Qimantage area of East Kunlun Mountain, Qinghai Province, is characterized by porphyrytype mineralization. The authors have conducted geochronological study on the samples from the orebearing porphyry and orebodies by SHRIMP zircon UPb and molybdenite ReOs dating, respectively. The zircon UPb age for the Kfeldspar granitic porphyry is 224±1.6 Ma while the ReOs age of ore molybdenite is 224.7±3.4 Ma, suggesting that diagenesis and mineralization took place coevally with the intense crustmantle interaction in the East Kunlun orogenic belt in Late Indosinian. Meanwhile, the interaction between crust and mantle resulted in largescale magmatichydrothermal activities and metallogeny. The Kfeldspar granitic porphyry is closely related to polymetallic mineralization and the mantlederived diorite, diabase and gabbro in the area both temporally and spatially. It is refered that that the magmatic intrusives mentioned above are all the products of the crustmantle interaction. Based on the geochronological study, it is proposed that the Yazigou deposit has the same geodynamical setting as the whole Eastern Kunlun orogenic belt in Late Indosinian. Meanwhile, the authors also point out that there are good potentials for porphyry deposit prospecting in the area.