On the basis of detailed investigation of geological setting and ore deposit features, this paper deals with geochemistry and sulfur and lead isotopes of Xiaogouli-Sanyangba gold deposit in Xihe-Chengxian basin, Gansu Province. The results show that the Co/Ni of pyrite is mostly more than 1 indicating that the ore-forming material is derived from magmatic-hydrothermal fluid. Analysis showed that in liquid pahse Na+, K+ are the dominant cation and Cl- the dominant anion, in gas phase H2O and CO2 dominant. The homogenization temperature, salinity range in 115 ℃ to 205 ℃ and 7.2% to 11.5%, respectively. The ore fluid is mainly composed of meteoric water.