The Suishigou granitic pluton is located in Muztag area,western part of the east Kunlun orogenic belt and is one of the main granitic plutons within the area.In order to find out the genetic types,material sources and formation ages of the pluton,and further discuss the regional tectonic evolution history of Muztag area in East Kunlun.Methods: Detailed geological survey,petrology,LA-MC-ICP-MS zircon U-Pb dating of monzogranite and whole rock geochemical of the Suishigou igneous rocks in Muztag area,East Kunlun,Xinjiang.Results: Petrological study shows that the pluton is characterized by high silicon,high alkali and rich aluminum (SiO2=67.54 %～71.56 %),Na2O=3.08%～4.50%,K2O=3.05%~4.20%,Al2O3=14.26%～16.58%),belonging to the metaaluminous to weakly peraluminous high-K calc alkaline series.They display high REE contents (126.25×10-6~160.13×10-6),enrichment in LREE,Rb,Th,K,depletion in HREE,Nb,Ta,Hf,Sr,and slightly negative Eu anomaly (δEu=0.68~0.84).On this basis,we suggest that the studied granitoids belong to I-type granite.The zircon U-Pb age of the pluton is 208.0 ± 1.1 Ma (MSWD=1.0),indicating the Suishigou granitic pluton is formed in the Late Triassic.Conclusions: Combined with the characteristics of regional tectonic evolution,the Shizigou granite was derived from partial melting of lower crust,and there was underplating of mantle derived magma and mixing of crust mantle magma during its formation.Its tectonic setting was post collisional environment.