Xiaochigou Gold Deposit is located in the middle of Xiongershan metamorphic core complex in Qinling orogenic belt.Based on the analysis of sulfur and lead isotopes in altered rock type ores formed in the main metallo-genic stage of the deposit,it is found that the δ³⁴S of sulfur isotope of the deposit is between -3.05 ‰ and 10.93 ‰,mostly remaining within the range of meteorite sulfur,indicating that the sulfur mainly comes from the mantle with the addition of crustal sulfur,which reflects the sulfur isotopic composition of mantle sulfur after being mixed with crustal materials.The lead isotope ²⁰⁶Pb/²⁰⁴Pb value is 17.09-17.53,²⁰⁷Pb/²⁰⁴Pb value is 15.31-15.61,and ²⁰⁸Pb/²⁰⁴Pb value is 37.20-38.10.The variation range is not wide,belonging to normal lead range.Lead isotopic characteristic parameters and related diagrams show that the lead in ores has crust-mantle mixing characteristics.The sulfur and lead isotope compositions show that the ore-forming materials of the deposit are mainly mantle-derived materials,and the deep mantle-derived materials are mixed with crust-derived materials.