The migration and precipitation of metal elements are key factors in the formation of hydrothermal deposits. By far, metallic ions in ore forming fluid is considered migrating as complex of S and halogen elements. The metallic ions in the fluid forming MVT lead—zinc deposits is considered migrating as complex of halogen element, because the ore forming fluids are rich in Na+、K+、Ca2+、Mg2+ and Cl-、F-、CO2-3, poor in HS- and S2-. Therefore, import of H2S is indispensable in deposition of lead and zinc sulfides in MVT lead—zinc deposits. There are close temporal and spatial relationships between the H2S rich gas in Sichuan basin and the MVT lead—zinc deposits around the basin. This implies that the S in the MVT lead—zinc deposits probably comes from the H2S rich gas. The bitumen bearing lead—zinc sulfide deposits are formed within the oil reservoir. The lead—zinc sulfide deposits without bitumen are formed outside the oil reservoir. When copper bearing hydrothermal fluid mixed with petroleum, the petroleum becomes into H2S poor gas and bitumen by the heat of the hydrothermal fluid. The reduction of the gas results in the deposition of the copper ion in the hydrothermal fluids as native copper, forming the bitumen bearing native copper deposits in the Emeishan basalts. More over, the corrosion from H2S can provide the space for Zn—Pb—Cu deposition.