Qikou Sag, as a typical dustpan-shaped sag in Bohai BayBasin, experienced multi-stage structural evolution and multi-cycle deposition. As a result, various types of hydrocarbon reservoirs were generated in this area. In the central uplift belt, the oil and gas migrated vertically along the major fracture and induced the composite reservoirs form with different depths （low-medium-deep）. Otherwise, in the sag and slope where the fractures were not developed, the oil and gas mainlymigrated horizontally in the source rock strata and formed the stratigraphic lithologic reservoirs which distributed in a large area. Thus complicated superimposed reservoirs and full-sag oil bearing pattern in the rifted lake basin formed after all. Meanwhile, those advantageous phase regions, such as the formation with high quality source rocks, the major sand body belts, the regions with positive structure setting, the reservoirs with abnormal high pressure and special lithology （carbonate rock, igneous rock）, will become the important exploration target for oil and gas enrichment.