Abstract: H. O, S, Pb isotopic date of the mesothermal Au deposits in Tongbai -Dabie area were collected and sorted out. Analysis of the results showed that there were different sources about fluids, sulfur and ore -forming elements in metallogenic fluids. The fluids mainly belong to precipitate waters, and sulfur and ore -forming elements came from some types of rocks that the fluids went through when the fluids permeated down and returned up in the continental crust. The Au minerallization scales in this area obviously were influfluenced by the characters of the metallogenic fluids.