Kuzigan potassic alkaline complex mass is composed of alkali syenite and granite. Syenite is mainly composed of potassium feldspar and diopside, while granite is composed of potassium feldspar, plagioclase, quartz and diopside. The pyroxenes in the rocks are identified as calcium pyroxene, including diopside and hedenbergite. Petrogeochemical analysis shows that these rocks belong to potassic alkaline series with high alkali, potassium and calcium. Moreover, the rocks are enriched in the large- ion lithophile elements (LILE, Rb, Ba, Th, U and Sr) and Pb, but depleted in high field strength elements (HFSE, Nb, Ta, Zr, Hf and Ti). Rare earth element (REE) content ranges from 372. 37×10 -6 to 1218. 07×10 -6. The ratio of LREE/HREE is relatively high (21~37), and weak Eu negative anomalies (Eu/Eu*=0. 66~0. 84). Systematic LA- ICP- MS and SHRIMP U- Pb zircon dating results indicate ages of diopside syenite and diopside granite are 11. 7±0. 1 Ma and 11. 0±0. 3 Ma, respectively, which belong to the Himalayan period, equivalent to the end of the Miocene. The εHf(t) values of the zircons from the two types of rock range from -9. 4 to -5. 5, which plot between those of chondrite and the lower crust. The results show that the collision between the Indian continent and the Eurasian continent caused the lithosphere in the West Kunlun and Karakoram area to be shortened and greatly thickened, leading to the delamination of the thickened lithosphere and the upwelling of the asthenosphere material and the re- melting of the thickened lower crust material. With the extension and uplift of the crust, Kuzigan potassic alkaline complex mass was formed.