Based on the geologic dissection of Fuyang reservoir in southern Songliao Basin, the accumulation pattern of “sweet point” is divided into “Directly expulsion” type and “Fault supply oil” type. The source rocks, reservoir，sedimentary source and fault are considered as the main controlling factors for the formation of “sweet point”. High quality source rocks supply abundant oil sources, and anomalous pressure is the major driving force for hydrocarbon expulsion. Oiliness of the sand group Ⅰand Ⅱis better than that of group Ⅲ and Ⅳ in Quan 4 member. The reservoir thickness is more than 3 meters. The main sedimentary facies are river channel and flood land. The oiliness of the main river channel sand body in Tongyu sedimentary source is better than in Baokang sedimentary source.