The Pusangguo lead-zinc polymetallic deposit is located in the volcanic-magma arc of the southern Gangdise metallogenic belt, Tibet. The skarn type orebodies mainly occur in nearly bedded and lenticular shapes in nearly east-west direction and are hosted in the skarnized marble of the Cretaceous Takena Formation, with lots of skarn minerals developed in this deposit. In order to further identify the species of skarn minerals and types of the skarn and analyze the formation environment of the skarn and its relationship with mineralization types, the authors analyzed the chemical composition of the skarn minerals by using the electron microprobe technology and on the basis of the systematic microscope observation. According to the results obtained, the garnet is mainly composed of discontinuous isomorphism of andradite and grossular (And_47.39~98.17Gro_0.59~50.22Ura + Pyr + Spe_0~3.53), the clinopyroxene is mainly composed of hedenbergite-johannsinite-diopside (Hd_37.91~74.16Jo_0.91~61.66Di_0.43~46.07), the pyroxenoid is mainly wollastonite, and the endmember compositions are Wo_99.09~99.26En_0.50~0.56Fs_0.13~0.24. In addition, the hornblendes are mainly magnesium hornblendes and have the features of calcium hornblende, the epidote is relatively enriched in aluminum and calcium but poor in iron and magnesium, and the chlorite belongs to the type of pycnochlorite. The skarn mineral assemblage characteristics indicate that the skarns in the Pusangguo deposit have the features of both calcium-skarn and manganese-skarn. At the early stage of skarn mineralization, the skarns were mainly formed under the conditions of high temperature, pH, oxygen fugacity, and the ore-forming fluid had high oxygen fugacity. Manganese skarn mineral characteristics and the single silver minerals show that this deposit has the silver ore prospecting potential, which can serve as the next step prospecting direction in the future exploration.