The Xinhuoshan and Wulaxi granite plutons are located in the Jianglang dome, which is a key domain for providing deep insight into the tectonic evolution of the Songpan- Ganzi orogen. This study presents zircon U- Pb chronology, geochemistry and Hf isotope data to explore their petrogenesis and metallogenic implications. Zircon U- Pb dating provides crystallization ages of 162±1~170±0. 5 Ma for the Xinhuoshan granite and the Wulaxi granite. Both granites are composed chiefly of quartz, K- feldspar, plagioclase with minor biotite. They are characterized by low A/CNK (1. 10 ~0. 99), TFeO/MgO (8. 55~2. 83) and K 2O/Na 2O ratios (1. 34~0. 51) with low Zr+Nb+Ce+Y concentrations (average 258×10 -6) and zircon saturation temperatures (781~651℃). Their Al 2O 3, P 2O 5 and SiO 2 contents show negative correlations, and they thus fit the I- type granite definition. Some major and trace elements exhibit strong correlations, implying extensive fractional crystallization (e. g. , hornblende and ilmenite) during the magma evolution. Two granites show enrichment in light rare earth elements and large ion lithophile elements, and depletion in high field strength elements. They have low Mg# values (38. 7~17. 3) and Y/Nb ratios (0. 45~0. 16), and yield dominantly negative ε Hf( t ) values (-24. 8~-7. 6), indicating a heterogeneous source and their derivation from remelting of ancient continental crust (e. g. , Mesoproterozoic Liwu Group in this region) with minor juvenile crust or contaminated by the mantle materials. Combined with prior studies, we conclude that the Xinhuoshan and Wulaxi granites were formed in the Middle Jurassic magmatic activity. The structural transformation of collision orogeny and post collision extension resulted in the formation of the Middle Jurassic magma by partial melting caused by decompression.