style="MARGIN: 0cm 0cm 0pt" class=MsoNormal>///The Yixingzhai gold deposit is a large-size quartz-vein type ore deposit. The ore microscopy and measured temperature data of fluid inclusions reveal that inclusions at various ore-forming stages of the Yixingzhai gold deposits are mainly gas-liquid two-phase (H2O or H2O-CO2) inclusions and subordinately pure volatile inclusions. Raman analysis of the fluid inclusions indicates that, in the gaseous phase, SO2, CO2 and C6H6 are existent at ore-forming stage style="FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体">Ⅰ, and SO2 is existent at stagestyle="FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体">Ⅱ in addition to water vapor. The ore-forming fluids are of the epithermal-mesothermal and low salinity hypothermal system. The ore-forming fluids boiled very impetuously at the main stage, the meteoric water participated the activity during the late stage, and the ore-forming fluids were mixed with other fluids from different sources at stage style="FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体">Ⅱ.