The Shibancun biotite monzo granites in the Mengyang Village of Lianghe county―Shiban Village, Mangshi County, are located in the Tengchong Block, western Yunnan. The Shibancun biotite monzo granites are mainly composed of biotitic monzogranites. Most of the Lianghe granites is from the original Gaoligong Group disintegration by the author through the 1∶50000 regional geological mapping. To limit the precise age of the Cenozoic magmatic mineralization in the Mangshi area, the Lianghe granites have been analyzed using LA ICP MS zircon U Pb techniques and geochemical methods. The zircon LA ICP MS dating indicates that the biotite monzo granites was emplanced at 125.60±1.0Ma. The granite is formed in the Early Cretaceous. Geochemical data show that the Lianghe granites are k black to high K calc alkaline and peraluminous to strongly peraluminous series,characterized by high content of SiO2（70.70%～76.14%）, the medium to high K（K20/Na20=1.12～2.37）and peraluminous ratio( A/CNK)= 0.67～1.17). ACF plot indicate that the Lianghe granites are S type granites. Lianghe granites are also enriched in Rb、Th、U、Nd、Sm and Pb，but strongly depleted in Nb、Ce、Sr、Eu、Zr and Hf. The REE content is between80.55×10-6and 362.85×10-6, average 171.97×10-6 ,with ( La /Yb)N ratios of 5.11～18.80 and δEu of =0.28～1.08. REE diagram shows rightward incline and obvious negative Eu abnormity. The intrusion is remarkably characterized by enriched LREE and depleted HREE. The chondrite normalized REE patterns show negative Eu anomalies. Magma source is probably rising and emplacement of partially melt granitic magma dominated by greywacke , which is typical of crustal genesis. The biotite monzo granite was derived from partial melting of the Mesoproterozoic metamorphosed basement (Gaoligong Group)。According to geochemistry and the trace element discrimination diagrams for tectonic interpretation,the the Cenozoic granitoids are considered to be of the post collision type formed in a transitional tectonic setting from the compressional system to the tensional system. The Gangdese—Tengchong block tectono magmatic orogenesis was intimately related to the closure and subduction and collide orogenesis of between the Qiangtang—baoshan plate and Gangdese—Tengchong massif. The determination of the Lianghe granites’s crystallization and origin provides new evidence for the Cenozoic tectonic evolution of the Tengchong massif．