Abstract: In order to study the genesis of Lixi-type copper deposits,fluid inclusions from 3 typical Lixi-type copper deposits were selected for petrographic,microthermometric,and laser Raman compositional analysis.The petrographic and microthermometric results revealed 5 types of inclusions in the mineralizing stage,including gas-liquid two-phase inclusions,daughter mineral-bearing inclusions,liquid CO2-bearing inclusions,pure liquid inclusions,and pure gas inclusions;the gas-liquid two-phase inclusions and daughter mineral-bearing inclusions showed consistent fully homogeneous temperatures (average 191.42 ℃ and 170.33 ℃,respectively),but with significant salinity variations,indicating boiling of the ore-forming fluids and its importance in mineralization;the fully homogeneous temperatures of the late-stage fluid inclusions ranged from 319.00 ℃ to 425.00 ℃,significantly higher than those of the main mineralizing stage,indicating the modification of the mineralizing fluids by late-stage hydrothermal activity.Laser Raman compositional analysis results showed that the gas phase composition in the mineralizing fluids is dominated by CH4 and H2O,followed by CO2,with occasional presence of N2 and pure gas-phase CO2,suggesting a reducing H2O-NaCl-CH4-CO2±N2 system.Based on the geological conditions and mineralization alteration characteristics of the Lixi-type copper deposits,as well as the study of fluid inclusions,the Lixi-type copper deposits are classified as sedimentary-reformed deposits.