Abstract: In order to confirm the hydrocarbon source rock development degree of Nenjiang formation and the relation between crude oil from member-4 and source rocks of member-1 and member-2,through systematic sampling and evaluation of potential index of source rocks of member-1 and member-2 from Nenjiang formation,by adopting the organic carbon,rock pyrolysis and saturated hydrocarbon mass spectrometry method of color,the organic carbon of hydrocarbon source rocks in Nenjiang formation is more than10%and the hydrocarbon generation potential amount is more than 100 mg/g,and the organic matter types are typeⅠ,typeⅡ1,and typeⅡ2,generally of sapropel type- humus sapropel type,and the organic matter type is good.Through fine correlation of molecular geochemical characteristics between crude oil in member-4 and source rocks of member-1 and member-2,and those in Qinshankou formation,the crude oil in member-1 top,member-2 bottom and that of in member-4 of Nenjiang formation are proved to have the genetic relationship.