1. College of Earth Sciences，Jilin University，Changchun 130061，China; 2. China Petroleum Exploration and Development Research Institute，Langfang 065007，Hebei，China; 3. College of Geo-exploration Science and Technology，Jilin University，Changchun 130026，China

Field outcrop，drilling and seismic data are analyzed in order to investigate the oil and gas geological characteristics of the Late Paleozoic Linxi Formation in Binbei area of the Songliao Basin． The research results show that the Late Paleozoic Linxi Formation in Binbei area developed thick layers of dark mudstone，which thickened towards the interior of the basin． The organic matter abundance of the Linxi Formation dark mudstone was 0. 96% ～ 2. 79%，and its Ro was 2. 28% ～ 5. 53%，belonging to the high-over-mature stage． The organic matter types are mainly type II and III kerogen，which are effective source rocks． The development area of source rocks has been delineated according to the thickness of dark mudstone，which is mainly distributed in the Lindian fault depression and the Renmin town area．