1. College of Earth Sciences��Jilin University��Changchun 130061��China 2. Wangqing Huaxin Mining Co�� Ltd. ��Wangqing 133212��Jilin��China

The Ciweigou gold deposit is one of typical low-sulphidation epithermal gold deposits in NE China�� In order to determine its physical and chemical conditions and ore-forming depth��the microthermometric and laser raman spectrum analysis of fluid inclusions in the quartz and calcite from the same auriferous quartz-calcite vein in different levels are carried out�� There are major gas-liquid two-phase and small amount of liquid phase fluid inclusions in auriferous quartz-calcite vein�� The homogenization temperature of the two-phase inclusions ranges from 112. 2 �� to 377. 7 �� and mainly from 200 �� to 240 ��; the salinity ranges from 0. 18%NaCl to 10. 87%NaCl�� and the average value is 3. 43%NaCl; the density changes from 0. 57g /cm3 to 1. 00 g /cm3 and the average is 0. 89 g /cm3 �� Together with the Raman spectra of gas phase in fluid inclusions��characteristics of the fluid inclusions show that the ore-forming fluid belongs to NaCl-H2O ( CO2 ) hydrothermal system with low temperature��salinity and density�� According to the microthermometric data��the value of ore-forming pressure can be estimated from 7. 99 to 37. 89 MPa and the mean value is 14. 92 MPa�� The depth of the mineralization is from 0. 27 to 1. 26 km��averaging 0. 50 km�� Based on the comparision between the Ciweigou deposit with other epithermal gold deposits��it can be concluded that the small denudation depth of the Ciweigou deposit demonstrates the preferable ore prospecting in this deposits��