Abstract: Generating and ejecting hydrocarbon history of the research area is simulated on the basis of buried and thermal history.The simulation of generating and ejecting hydrocarbon history is the effective means to forecast the oil and gas potential.The generating hydrocarbon intensity cneter is Niuju-Qinglongtai depression,showing the there were generating hydrocarbon center in northern section of the East Sag that is the basis of petroleum systems.There are three set of hydrocarbon rocks i.e.Shasan,Shayi and Dongying Members.The high peak of the hydrocarbon ejecting qualities of all periods was reached at the end of Dongying Member deposition,reflecting the significant influence of dextral strike-slipping movement at the end of the period,which is the stronger evidence of oil and gas episode asembling.The center of ejecting hydrocarbon intensity is located in Niuju-Qinglongtai depression and hydrocarbon assembled dispersedly to the side laterally,so besides Niuju-Qinglongtai structural belt,Ciyutuo high rampart belt and eastern steep slope belt are also advantageous position of hydrocarbon assembling.The qualities of hydrocarbon ejecting were maximum at the end of Dongying Member deposition,account for 35.87% of oil ejecting,90.2% of gas ejecting,Shasan Member was the second,which demonstrated there are two critical moment of the petroleum systems in the area.