Abstract: Based on field geological survey,excellent black mudstone - shale hydrocarbon was found to be developed in the South Margin of the North China Platform,which was mainly distributed in Dongpo formation(western Henan)/top of Yutaishan formation and bottom of Fengtai formation (southern Anhui).The lithology belongs to black mudstone -shale containing phosphor,shale,dark gray muddy limestone. In the plane,the source rock was mainly developed in Continental margin and the platform margin slope,the thickness presenting the trend of increasing,from north to south and from west to east.The organic matter abundance is high (organic carbon >1.7%),and increases with the thicker of thickness.It belongs to kerogenⅠand thermal evolution is higher and affected by gravity sliding tectonic(R_o> 2.5%). Although with the small thickness,it had a strong hydrocarbon potential and was evaluated to be a high - quality hydrocarbon source rock,which has the value of exploration.