Abstract: Hydrocarbon enriched depressions in Bohai Bay Basin is rich in oil and gas resources. Lithological stratigraphic oil and gas reservoirs and subtle buried hill oil and gas reservoirs are the important exploration targets for discovery of large-scale reserves in the future. Guided by the new knowledge about hydrocarbon accumulation theory and based on advanced exploration technology, Huabei Oilfied Company has developed a new mindset of òsecondary explorationófor hydrocarbon enriched depressions. It also comes up with the secondary exploration method for hydrocarbon enriched depression, which is focused onòcomprehensive knowledge, comprehensive assessment and comprehensive deployment.óThe method includes construction of 3D seismic data platform for the whole depression, re-construction of geological models for the structure, sedimentation and reservoir of depression, re-description of quantitative characteristics of hydrocarbon distribution, creation of multi-area hydrocarbon accumulation models, and unfolding comprehensive preliminary exploration of multi-area targets. This method is of great realistic significance to exploration of hydrocarbon enriched depressions in Bohai Bay Basin and increase of large-scale reserve through sustainable exploration.