Abstract: Based on the analysis of the tectonic setting,source-reservoir-caprock development,evolution and preservation as well as some typical examples of the Lower Marine Assemblage,it is considered that the source rock in the Lower Marine Formation Assemblage in the Meso-Cenozoic superposted area in the north of Lower Yangtze basin is characterized by long-term and multiperiodic hydrocarbon-generating.Moreover,the Silurian Gaojiabian Formation being composed of thick marine mud shale is a good caprock.Further research shows that the Lower Yangtze area is a fossil plate spliced to the Eurasia in Indo-Chinese epoch.The main body of the fossil plate is a relatively steady zone called Lower Yangtze central steady zone.This central steady zone is situated in Yancheng to South Yellow Sea region.It is a potential exploration area in the Lower Marine Formation Assemblage in Lower Yangtze region.