1. State Key Laboratory for Mineral Deposits Research，School of Earth Sciences and Engineering，Nanjing University， Nanjing 210046，China; 2. East China Mineral Exploration and Development Bureau of Jiangsu，Nanjing 210007，China

On the basis of the research on geological background and characteristics of Dajingou glod deposit， the authors conducted petrographic observation and microthermometry on fluid inclusions from the gold- bearing quartz veins． The results show that most fluid inclusions in the samples are liquid- rich two phase gas- liquid inclu- sions，occasionally pure liquid or gas inclusions． These liquid- gas phase inclusions could be divided to low temper- ature (75℃ ～ 121℃) and high salinity (16. 71 wt% NaCl ～ 19. 68 wt% NaCl)，low temperature (100℃ ～ 172℃) and low salinity (0. 7 wt% NaCl ～5. 71 wt% NaCl)，low- middle temperature (75℃ ～253℃) and low- middle salinity ( 6. 16 wt% NaCl ～12. 51 wt% NaCl) and high temperature (331℃ ～ 420℃) and low- middle salinity (4. 96 wt% NaCl ～12. 51 wt% NaCl) inclusions． Homogenization temperatures and salinity of these fluid inclusions vary from 75℃ to 253℃ and 0. 7 wt% NaCl to 19. 68 wt % NaCl，respectively，without obvious linear relationship between them． The research results show that the fluids of Dajingoud gold deposit is typical middle- low salinity fluid system，similar to the orogenic metamorphic fluid，which resembles orogenic gold deposits．