CO2 气是一种特殊类型的天然气 ,其成因和富集规律与烃类气有着显著的差别 .运用CO2 气碳同位素、伴生气等地球化学资料 ,探讨了松辽盆地CO2 气的成因 ,分析了CO2 气藏分布与深断裂带、区域盖层、深部侵入岩、火山岩分布关系 ,指出了长期活动的深断裂带、深部热流底辟、良好盖层是CO2 气藏的成藏条件 ,给出了CO2 气藏成藏模式 ,进而指出松辽盆地CO2 气藏的勘探方向 CO2 gas is a special kind of natural gas, and its genesis and enrichment rule are obviously different from that of hydrocarbon gas. The origin of CO2 gas in Songliao Basin was discussed by using the carbon and carbon isotopes of gas, associated gas and other geochemical data. The distribution of CO2 gas reservoir is related to the distribution of deep fault zone, regional caprock, deep intrusive rock and volcanic rock. The deep fault zone with long-term activity is pointed out. Deep thermal flow diapirs and favorable caprock are the accumulation conditions of CO2 gas reservoir. CO2 gas reservoir accumulation model, and then pointed out that the Songliao Basin CO2 gas exploration direction