Detailed fluid inclusion and H-O isotope characteristics of metallogenic period quartz veins were studied to reveal the ore-forming fluid features. Petrography and microthermometric studies of fluid inclusions suggest that the main types of fluid inclusions of the Malian gold deposit are gaseous inclusions, liquid inclusions and pure liquid inclusions. Temperature test shows that the homogenization temperature and salinity of fluid inclusions vary from 148 to 255℃, mostly in the range of of 180−210℃, and 1.7%−7.5%NaCleqv (the peak values vary in the range of 2%−4%NaCleqv), respectively. Based on these results, the authors have reached the conclusion that the ore-forming fluids of the Malian deposit should be of low temperature and salinity. Laser Raman and group fluid inclusions content studies indicate that gas composition of the ore-forming fluids are mainly H2O, with some CO2 and CH4, whereas liquid compositions of the ore-forming fluids are mainly Ca2+, Na+, SO42−and F−, with some K+, Mg2+, NO3−and Cl−. The ore-forming fluids are then defined to be of the NaCl−H2O±CO2±CH4 system. The hydrogen and oxygen isotopic compositions of the ore-forming fluids show thatδDV-SMOW values of the ore-forming fluid are between−92.3‰and−113.6‰, andδ18OH2O are between 2.5‰and 3.5‰, which indicates that the ore-forming fluids were derived from the mixing of magmatic water and meteoric water. Based on the characteristics of ore-forming fluids, it is concluded that gold deposition in the Malian gold deposit was related to the phase separation.%提为确定马连金矿成矿流体性质，笔者对成矿期石英开展详细的流体包裹体和氢氧同位素研究，包裹体岩相学和显微测温结果表明：石英中主要发育气相包裹体、液相包裹体和纯液相包裹体；包裹体均一温度为148~255℃（峰值为180~210℃），盐度为1.7%~7.5%NaCleqv（峰值2%~4%NaCleqv），属于低温、低盐度金矿床。激光拉曼和群体包裹体成分分析显示：成矿流体气相成分以H2O为主，CO2、CH4次之，液体主要成分为Ca2+、Na+、SO42-和F-，其次为K+、Mg2+、NO3-和Cl-，成矿流体属于NaCl-H2O±CO2±CH4体系。包裹体氢氧同位素研究表明：成矿流体δDV-SMOW值介于-92.3‰~-113.4‰，δ18OH2O值介于2.5‰~3.5‰，具有岩浆水和大气降水混合的特征，结合成矿流体特征，认为流体不混溶或沸腾作用导致相分离是马连金矿沉淀主要原因。
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