Himalayan granitoids in western Qinghai_Xizang plateau are distributed near the Taaxi-Hongshanhu suture. The rock assemblage is of diopside syenite-diopside granite-biotite (monzonitic) granite type. The rocks consist mainly of K-feldspar, plagioclase, quartz, biotite, diopside and hornblende. Chemical composition is characterized by rich alkali and high content of potassium with high value of K 2O/Na 2O, rich Rb, Sr, Ba, Th, U and LREE. Sr and Nd isotopic composition shows mantle characteristics. All these feature indicate that the rocks are of shoshonitic series.