Abstract: A numerical simulation system of pool-forming history was established by modelling the development history of source rocks,reservoirs,cap rocks and traps as well as primary migration,preservation conditions,paleotemperature and pressure.As an example,it was used in the Paleozoic of the Wen'an (Slop,the Bohaiwan Basin.The results showed that the Paleozoic coal-related hydrocarbon pools in the) Wen'an Slope of the Bohaiwan Basin were formed in the two periods.The first was the end of the Meso-zoic,but the formed pools were disrupted by the Yanshanian movement afterwards.And the second was the Palaeogene,which was the major period of pool formation.The formation of hydrocarbon pools in the study area mainly depended on the matching of hydrocarbon-generating history and hydrocarbon-expelling history to trap formation periods and the preservation conditions of hydrocarbon pools after their formation.So the exploration for the Paleozoic original hydrocarbon pools in the Jizhong Depression should be focused on the traps formed in the Himalayan period and situated within and around the secondary hydrocarbon-generating areas.