Abstract: Wudaogou area is located in the eastern section of the Central Asian orogenic belt,and the northwestern section of Heihe-Hegenshan fault.There are intense structural and magmatic activities in the area and develop Indosinian intrusions and 2 groups of NE-trending faults,which are favorable geologic conditions for gold mineralization.The gold mineralization in the area is dominated by quartz veins,and the mineralization can be divided into quartz-pyrite-gold stage (Ⅰ),quartz-pyrite-chaloopyrite-sphalerite stage (Ⅱ),and calcite-poor sulfide stage (Ⅲ);and associated with the alteration of chloritization and sericitization.Research on fluid inclusions shows that there are 3 types of fluid inclusions:gas-liquid two-phase inclusions(L-type),CO2-containing inclusions(C-type),and gas-rich inclusions(V-type).The Ⅰ,Ⅱ and Ⅲ stages of mineralization gradually evolved from the CO2-NaCl-H2O system with medium high temperature and medium salinity to the NaCl-H2O system with low temperature and low salinity.