Abstract: Kangxiwa group based on mesometamorphical lithostratigraphic unit of Triassic Shaksgam River groups is newly separated from the job of four Kangxiwa 1:250000 regional geological survey works. Distributed in the southern area of the late Kangxiwa brittle faults, the strata are mainly composed of medium-deep mesometamorphical clastic rocks and little marble, and intruded by the Cambrian and Jurassic granite. Characteristics of petrology, metamorphism, deformation, trace element and rare earth element of the group were studied and compared in details with Ailiankate group. Results show that the two groups are basically identical and should be classified as the same tectonic rock strata unit. It is further demonstrated that the west Kunlun Mountain has the same basement evolution characteristics with the Tarim block. The redefinition of strata provides reliable information for material composition and evolution studies of west Kunlun.