Abstract: Qudi area is the most abundant hydrocarbon structural zone in the south slope of Huimin Sag.With the development of exploration,the difficulties of exploration is increasingly growing and the exploration direction is also not clear.In order to search for hydrocarbon enrichment area and summarize accumulation regularity,the accumulation elements need to be further clarified.Based on study of the oil deposits distribution features and through the oil deposits anatomy and studying the accumulation elements,the hydrocarbon migration and accumulation regularity have been summarized and the hydrocarbon enrichment has been identified.Research shows that the hydrocarbon injecting area is controlled by the concealing and opening in different segment of Xiakou fault,the hydrocarbon zones are controlled by the third-level faults and these zones are divided into blocks by fourth-class and fifth-class faults,hydrocarbon accumulation of the nose structural peak is controlled by the reservoir distribution and denudation lines,denuded zone in the southern of Qudidong nose structure is perhaps the hydrocarbon accumulation area.