1�� College of Earth Sciences��Jilin University��Changchun 130061��China; 2�� Jilin Haigou Gold Mining Co����LTD��Antu 133600��Jilin��China

Haigou gold deposit is a typical orogenic gold deposit�� There are a reasonable amount of fluid inclu- sions in the gold deposit�� including three types: CO₂ -H₂O- NaCl inclusions�� pure CO₂ inclusions and NaCl- H₂O inclusions��of which most of them are CO₂ -bearing inclusions�� The fluid salinity is 1.43% -9.08%��mainly concentrated in the range of 4.69%-5.41%��the density of CO 2 is 0.69 -0.80 g/cm³ ��indicating that the mineralization fluid is low- medium salinity and low density fluid�� A series of studies on gold- bearing quartz vein and fluid inclusions show that there exists a positive correlation between the degree of the gold mi- neralization and the amount of CO₂ in the inclusions��which means the more CO₂ - bearing inclusions there are��the higher the content of gold is�� CO₂ is mainly derived from mantle fluid��and the ore- forming fluid should be derived from mantle fluid and the crust shallow fluid�� The conclusions have important denotative meaning on the metal- logenic mechanism of orogenic gold deposit and the deep prospecting on metal deposit��