The zircons have high ratio of Th/U (0.63-1.28) and are magma originated for their internal oscillatory zoning on CL imagines of the Gerizhuotuo diorites in the Buqingshan tectonic mélange belt， and LA-ICP-MS zircon geochronological age of 225.8±1.5Ma (MSWD=0.53)， implying intruding at the early period of Late Triassic. Geochemically， the rocks have middle contents of SiO2， e.g. 53.07% - 58.74%， and relatively high Al2O3 (14.66% - 16.17%)， low alkaline (4.76% - 6.04%) ，high K2O（1.60％~2.90％）and Rittmann index σ from 1.69 to 2.66， belongs to the high-K calc-alkaline series. The average value of ΣREE is 158.36×10-6 ~211.50×10-6，δEu= 0.85 – 0.97. The chondrite normalized REE pattern curve is right-sloping type，and the rocks possess weak negative Eu anomalies. The primitive mantle standardized trace elements are characterized that HFSE(Nb， Ta， P，etc. ) and LILE(Ba、Sr，Ti，etc. ) has remarkable negative anomalies，Rb，U，La，Hf，Nd，etc. ) has remarkable positive anomalies. Gerizhuotuo diorite is formed in the high temperature environment (800 ° C ±)， with post-collisional magmatism characteristics， is the product of crustal partial melting after the collision of the the East Kunlun block and Bayan Har block.