Jilongshan skarn-host Cu-Au deposit located in west of Middle-Lower Yangtze River Fe-Cu metallogenic belt, its mineralization is closely related to exposed granodiorite porphyry. The main minerals of pluton are plagioclase, potassium feldspar, biotite, amphibole and quartz. Mineral chemical analysis results showed that plagioclase in rock is oligoclase-andesine, biotite is magnesian biotite and rich in Mg²⁺, Al³⁺, K⁺, depleted of Ca²⁺, MF changes from 0.47 to 0.64, amphibole is short of Ti ²⁺ (0.35%~1.78%) and rich in Mg²⁺(5.3%~9.35%). Mineral geotemperature and geobarometer showed that pluton consolidation temperature is 720 ℃~790 ℃, pressure is 4×10⁸ Pa~5×10⁸ Pa, which is equivalent to a depth of 13 km~15 km, and oxygen fugacity (LogfO₂) rangs from -10.5 to -14. Chemical composition of biotite and amphibole suggest the pluton is I type granite formed in orogenic zone environment and the mixture of crust and mantle.