Taking the Xiangkariwa and Zhenqin granites in the southeastern section of the Songpan—Garze Orogenic Belt as the objects, this paper studies petrology, petrogeochemistry, zircon U- Pb chronology and Lu—Hf isotope, and discusses the genesis and tectonic significance of the rocks. Based on the results, the Xiangkariwa and Zhenqin granites are biotite granodiorite and biotite granodiorite- porphyry, respectively. The content of SiO2 in the granite is 65.45%~70.04%, Al2O3 is 15.30%~16.69%, K2O/Na2O is 1.10~1.56, which belongs to the high potassium calc alkaline series rocks; The aluminum saturation index A/CNK is between 1.04 and 1.11, which is weaker than that of aluminum. In the standardized distribution map for rare earth chondrites, similar curve characteristics are shown, which is: light rare earth enrichment, heavy rare earth losses and "V" type right dipping characteristics negative Eu anomaly. The rocks are rich in Cs, Rb, Ba, Th, U, etc., and less in Nb, Ta, Ti, P, etc. The zircon n(206Pb)/ n(238U) weighted average age of the rock mass is 217.9~216.3Ma, which shows that it is the product of Late Triassic magmatism; the initial value of zircon Hf isotope n(176Hf)/ n(177Hf) is 0.282453~0.282543, εHf(t) value is -6.84~-3.50, with its age (TDM2) 1.48~1.69Ga in the second stage, suggesting that it may be an ancient crust. According to the geochemical characteristics of rock mass and regional studies, it is believed that the Xiangkariwa and Zhenqin granites were formed in the post Triassic collision tectonic environment.