Abstract: The lithology of Jinnikegaiman pluton is mid-fine grained monzonitic granite.The zircon U-Pb dating indicate that the age of monzonitic granite is (516.5±0.8)Ma, belongs to Early Cambrian.This monzonitic granite belongs to aluminous-peraluminous granite of calc-alkaline series.It is enriched in light rare earth element, with obvious fractionation between LREE and HREE.It has slight negative Eu anomaly, which is enriched in Rb, K and other large-ion lithophile elements, with depletion of high field strength elements, such as Nb, Ta, P, Ti and HREE.It was derived from lower crust and formed by the melting of igneous rock.According to the zircon U-Pb dating and regional geological background, it's believed that this pluton was formed in the environment of rift valley of Post-COLG and the west Kunlun has experienced a Post-COLG extension environment in Early Cambrian.