Abstract: In the exploration practice during recent years, the unconventional oil-gas resources of Nanpu sag in Bohai Bay Basin have demonstrated some exploration prospects. However, the evaluations on conventional and unconventional oil-gas resources are mutually separated and the evaluation results are not restrictive, which cannot reflect the actual condition. The joint quantitative evaluation of conventional and unconventional oil-gas resources is realized using the theoretical pattern of reservoir accumulation in whole petroleum system, which is expected to guide the future oil-gas exploration. The results show that Nanpu sag is bounded by lower limit of buoyance-driven hydrocarbon accumulation depth (BHAD), where the original hydrocarbon quantity of conventional oil-gas in a free hydrocarbon dynamic field (F-HDF) is 18.07×10⁸t, that of tight oil-gas in a confined hydrocarbon dynamic field (C-HDF) is 38.72×10⁸t, and that of shale oil-gas in a bound hydrocarbon dynamic field (B-HDF) under the bottom limit of oil-gas accumulation is 107.46×10⁸t. The joint evaluation results of three types of oil-gas resources show that the amount of shale oil-gas resources in Nanpu sag is 7 577.37×10⁴t, higher than that of tight and conventional oil-gas resources; the amount of conventional oil-gas resources is 7 074.37×10⁸t, ranking second in Nanpu sag; the amount of tight oil-gas resources is the lowest, namely 4 985.89×10⁸t. The joint evaluation results of these resources provide a guide for the discovery of shale oil in Nanpu sag, based on which tight reservoirs are discovered in Ⅳ and Ⅴ oil formations of the Member 3 of Shahejie Formation, thus providing technical support for the target optimization of conventional oil-gas in middle-shallow sequences.