Three sets of source rocks，namely the Yingcheng Formation，Shahezi Formation，and Huoshiling Forˉmation，occur in the south of the Changling faultdepression in the Songliao Basin.Among them，the ShaheziForˉmation shale with high TOC is considered to be themajor source rocks in the area.It ismainly distributed in inˉdependent subˉsag being strongly compartmentalized.The hydrocarbon kitchen controls the distribution of gas reservoirs and the hydrocarbonˉgeneration potential controls the fullness of gas reservoirs.Gas reservoirs in the area feature in multiˉstage hydrocarbon charging and late carbon dioxide charging.It is suggested that the front row structures and lithological traps near the hydrocarbon kitchen are the potential targets for gas exploration.