Dazhushan is located southwest of Xiaozhushan and belongs to Mesozoic's Late Yanshanian acidic intrusive granite. The lithology is mainly potassium feldspar granite and granite porphyry. Previous studies on the geochemical characteristics of Xiaozhushan have been conducted, while the geochemical study of Dazhushan granite remains blank. Methodologies: The ten samples were analyzed by petrography, main trace and rare earth elements of the whole rock, Lithium isotope, zircon U- Pb dating, and plagioclase electron probe. Results: The results indicate that, through the petrography analysis, the granite in the study area contains spodumene, pegmatite veins obvious, and rock type belonging to I—S granite. The samples are high silica granite (SiO2=66. 97%~74. 97%), high total alkali content (Na2O+K2O=8. 70%~10. 73%), belonging to peraluminous high potassium calc- alkaline series; Eu negative anomaly is obvious (δEu=0. 25~0. 56). Calculating the highly differentiated granities index: aluminium saturation index is (A/CNK=0. 91~1. 01); differentiation index (DI) is 87. 07~96. 65; zircon saturation temperature is 836. 26~862. 16°C; zircon Ti thermometers reflect magma crystallization temperatures range from 698. 52~738. 91°C。Geochronology shows that the sample age is 113. 1±0. 36 Ma, which is Early Cretaceous Laoshan granite. Conclusions: The granite in the study area has the tetrad effect of rare earth elements (TE1, 3=1. 04~1. 15) and a high oxygen fugacity, indicating that the granite pegmatite in the study area has the metallogenic potential of lithium deposit. The differentiation process of granite experienced the separation and crystallization of plagioclase, zircon, apatite and other minerals. Magma upwelling along the fractures of the island arc and continental collision subduction zone, forming highly differentiated granites with metallogenic potential.