Based on a comprehensive analysis of S, Pb, H, O isotope geochemical characteristics of the Laochang deep porphyry molybdenum (copper) ore bodies, this paper deals with concealed porphyry metallogenic source material in Lancang of Yunnan Province. Studies show that the main sulfide δ34S values of porphyry molybdenum (copper) ore bodies are between -3.99 ‰ and +1.8 ‰, concentrated in a narrow distribution area, with an average of -1.32‰.The results of S isotope show the crust-mantle characteristics with the mixture derived from the lower crust and the upper mantle. The data show that lead was derived not only from the formation but also from the ancient continental crust basement located in the lower part of the ore-bearing layer, deep mantle and volcanic magma.oft-com:office:office" />