The De’rbur PbZnAg deposit is a largescale deposit of this kind to occur in the E’rguna massif in the northern section of the Great Hinggan Mountains. Homogenization temperature and salinity in sphlerite and quartz, Laser Raman spectroscopy analysis and DO isotope characteristics of fluid inclusions were carried out to study the oreforming fluid features and sources of the deposit. Homogenization temperature and salinity of fluid inclusions in sphlerite and crumbly quartz of the main mineralization stage are 213~260℃ and 3.05%~9.6%NaCleq, respectively. While homogenization temperature and salinity of fluid inclusions in quartz veins in late mineralization stage are 175~210℃ and 3.53%~7.15%NaCleq, respectively. Laser Raman spectroscopy analysis results reveal that H2O and CO2 with minor CH4 are the main gas components of the fluid inclusions. The result also indicates a NaClH2O system with CO2 oreforming fluid in the deposit. Hydrogen and oxygen isotope study yields δDH2O values of -153.8‰~-149‰ and δ18O H2O values of -0.77‰~2.38‰ for the main mineralization stage, and δDH2O values of -141.4‰~-154‰ and δ18O H2O ranges of -2.27‰~-0.47‰ for the late mineralization stage. The oreforming fluid of the deposit should be a mixture of magma water and evolutional meteoric water. Oreforming fluids of the PbZnAg deposits in the E’rguna massif show similar origin, with characteristics of low to moderate temperature NaClH2OCO2±CH4 oreforming fluid system, suggesting a mixture of magma water with evolutional meteoric water.