///Dashui gold deposit is located in the south margin of west Qinling. On the basis of the study done by former experts, after studying systematically fluid inclusions of deposit, the authors supposes that the most inclusions within calcite are gaseous and fluid inclusions. In the inclusions contained gaseous composition include CH4, CO and H2, which indicate the oxidizing environment, and the fluid composition is composed of anions as SO4-2 first and Cl- second, cations as K+ first, Na+ second. Au migrated in the complex of AuSO4 within the metallogenetic fluid. The metallogenetic temperature is