It is significant to distinguish the dynamic systems of petroleum accumulation(DSPA) for the understanding of petroleum accumulation and distribution.According to the formation pressure framework,genetic types of petroleum and characteristics of conduit systems,three dynamic systems of petroleum accumulation were identified in the vertical profile in the Nanpu depression,Bohai Bay basin.The deeper DSPA(including formations Es_3 to Es_2) is a sealed system with high-overpressure and high-mature self-sourced oil.Most of the crude oil in the system accumulated in the periods of late Oligocene(23.5 Ma) and late Pliocene(2.4 Ma).The middle DSPA(including formations Es_1 to Ed_1) is an overpressured half-sealed system with mature or lower-mature self-sourced oil.The accumulation of oil in the system also occurred in the late Oligocene(23.5 Ma) and late Pliocene(2.4 Ma).The shallower DSPA(including formations Ed_2 to Q) is a hydrostatic system with lower-mature aliensourced oil from the middle system.Oil within this system accumulated only in the late Pliocene period.The oil in the shallower system migrated vertically along the faults from the formerly accumulated oil in the middle system by lateral migration along the sandbodies,whereas petroleum accumulation in the deeper system was mainly derived from the system itself by lateral migration along the sandbodies and rarely migrated out of the system.In this case,it seems that the deeper system is a more potential exploration prospect in addition to the other two proved favorable systems. It is significant to distinguish the dynamic systems of petroleum accumulation (DSPA) for the understanding of petroleum accumulation and distribution. According to the formation pressure framework, genetic types of petroleum and characteristics of conduit systems, three dynamic systems of petroleum accumulation were identified in the vertical profile in the Nanpu depression, Bohai Bay basin. The deeper DSPA (including formations Es_3 to Es_2) is a sealed system with high-overpressure and high-mature self-sourced oil. Host of the crude oil in the system accumulated in the periods of late Oligocene (23.5 Ma) and late Pliocene (2.4 Ma). The middle DSPA (including formations Es_1 to Ed_1) is an overpressured half-sealed system with mature or lower-mature self-sourced oil. Also included in the late Oligocene (23.5 Ma) and late Pliocene (2.4 Ma). The shallower DSPA (including formations Ed_2 to Q) is a hydrostatic system with lower-mature aldrin sourced oil from the middl in the shallower system migrated vertically along the faults from the formerly accumulated oil in the middle system by lateral migration along the sandbodies, while petroleum accumulation in the deeper system was mainly derived from the system itself by lateral migration along the sandbodies and rarely migrated out of the system. in this case, it seems that the deeper system is a more potential exploration prospect in addition to the other two distinct favorable systems.