Abstract: The Tiantangshan tin polymetallic deposit is located in the eastern part of the Nanling metallogenic belt, near the junction of the Heyuan deep fault zone and the Dadongshan-Liyuan-Luofu east-west deep fault zone, and the middle and southern margin of the Mesozoic Dachangsha volcanic rock basin.Based on the analysis of the ore-forming geological conditions of the deposit, this paper carried out related research on the sulfur and lead isotope compositions of the ore and discussed the source of ore-forming materials.The sulfur isotope analysis of ore shows that the δ³⁴S_ΣS of the ore-forming hydrothermal fluid has two peaks, which are -0.5‰~0‰ and 5‰~6.5‰, respectively.According to the geological characteristics of the deposit and the sulfur isotopic composition of similar deposits, this paper believes that the initial sulfur source of the ore-forming hydrothermal fluid is mainly magmatic sulfur.During the mineralization process, the sulfur isotopic composition of the ore-forming hydrothermal fluid changed due to mixing with the shallow fluid.The lead isotope results of the ore show that the source of lead is related to the source area of the orogenic belt, which is mainly the lead from upper crust, and there may also be the participation of lead from mantle.Combining with the understanding of the large-scale mineralization of the Mesozoic in South China, basing on the exploration of the geological characteristics of the mining area, the evolution of metallogenic fluids and the source of metallogenic materials, this paper discussed the mineralization process of the deposit and put forward the ideas for prospecting, hoping to contribute to the prospecting and exploration work in the Tiantangshan area.