///The Maozu Pb-Zn deposit, a typical large Pb-Zn deposit in Sichuan-Yunnan-Guizhou Pb-Zn metallogenic province, is located on the western margin of Yangtze Block and hosted in the dolomite of Dengying Formation of Upper Sinian. The industrial ore-bodies are stratiform-like, vein and irregular shaped. Hydrothermal calcite and sulfide (sphalerite, galena and pyrite) are the main gangue and ore minerals, which were formed throughout the ore-forming process. C-O isotopic compositions of hydrothermal calcites, S-Pb isotopic compositions of sulfides were analyzed in this paper. It was showed that δ¹³CPDB and δ¹⁸OSMOW values of hydrothermal calcites varied in a narrow range of -3.73‰ to -1.95‰ and +13.80‰ to +14.95‰, respectively. All the geological and geochemical information show that the source of ore-forming metals and fluids of the Maozu Pb-Zn deposit is mixed product and the mechanism of mineralization could be explained by “fluids mixing” model.oft-com:office:office" />