Abstract： Jiangligou large porphyry - skarn tungsten (Cu-Mo) polymetallic deposit, measured in recent years ,is located in Tongren County, Qinghai Province.Tectonic position is in the northwest edge of Gang Cha pluton, northen of Mian-Lue suture zone -the western part of the Qinling orogen belt. Skarn tungsten (Cu-Mo) ores mainly occur as beded ，lenticular and pod-shape in the skarn between Jiangligou granite and Lower Permian Daguanshan group marble or Lower Triassic Longwuhe fine tuffaceous sandstone .Greisenization type of tungsten ore and porphyry copper ore are formed in the Jiangligou granite.16 samples from the three types of ores have been collected for Re/Os dating.The results of Re/Os isotope dating using ICP-MS method show Re/Os model ages arranging from 215.0 ± 3.0 Ma to 219.0 ± 3.7Ma, with a weighted average age of 216.85 ± 0.77Ma, a isochron age of 217 ± 1Ma (MSWD = 1.4). The deposit was believed genetically related to the tectonic – igneous- fliuid during Indosinian mineralization and formed in extension environment,after the collision in the Late Triassic in Qinling orogen belt.