Halagatu granodiorite rock，located in the eastern of the East Kunlun Mountains，hosts many mafic microgranular enclaves. The detailed field survey and petrology study and the LAICPMS singlezircons UPb age demonstrate that the mag matic age is （255.3±3.6）Ma of the granodiorite and （252.9±2.5）Ma of the dioritic enclave. The two ages are basically the same， which rules out the possibility that the mafic microgranular enclaves are xenoliths or residually refractory material of the magma source region，and the possibility that the mafic magma intrude after the consolidation of granitic magma. The result proves from the chronological aspect that Halagatu granodiorite rock is the product of magma mixing in Late Permian. The host granodiorite rock is the acid member，while the dark dioritic microgranular enclaves are the residually basic part of magma mixing. Mantlederived magma underplate under the regional compressive stress environment resulted by subduction of Animaqing ocean to the northward in the Late Permian， which caused transition between crust and mantle material，formed the magma chamber of magma mixing granite，and then intruded and formed the Halagatu rock mass.