Abstract: Tanjianshan Gold Field sits on the west part of Qaidam ultrahigh-pressure metamorphic belt.The gold deposits in the field are typical mesothermal fluid vein type gold deposits.U-Pb dating and Hf isotopic compositions of zircons from Xijinggou granite porphyry shows that zircons from Xijinggou granite porphyry yield weight mean 206Pb/238U age of 359.9 Ma±1.7 Ma(MSWD=0.15),its 176Hf/177Hf value is 0.282 515-0.282 788,and corresponding εHf(t) values range from -1.4-8.2 and the two-phase model ages (TDM2) are 743-1 238 Ma.These results suggest that the Xijinggou granite porphyry was derived from complicated source,and the magma source area should be dominated by Neoproterozoic juvenile accreted lower crust materials,mixed with Mesoproterozoic crustal materials.Based on the characteristics of regional tectonic evolution,it can be seen that the Xijinggou granite porphyry is the products of asthenosphere mantle upwelling and partial melting of lower crustal materials,which was formed in the post-collision extensional tectonic setting.The gold mineralization in Tanjianshan Gold Field is related to this granite porphyry.