Based on the geochemical characteristics of nalkanes, steranes, terpanes and the distribution of pyrrolic nitrogen compounds of nonhydrocarbons which can be utilized as parameters in evaluating the migrated oils, refering to results of structural study and oil source comparison, petroleum migration and accumulation of the Qintong sag, North Jiangsu basin, are discussed in this paper. The results are as follws: (1) The pyrrolic nitrogen compounds of crude oils in different structural belts reveal significant and dissimilar fractionation effect, which reflects the oil—source correlation distinctly: the high mature oils from the south fault belt migrated obviously, which are generated by the source rock of the 2nd Member(Ef2), Funing Formation, Eogene, in the Yuduo subsag; while the oils from the north part reflect slight fractional effect, suggesting that it migrated in a short distance, is generated by the source rock of the 2nd Member(Ef2), Funing Formation, Eogene, in the Chujialou subsag and also mingled by oils from the source rock of the Paleogene Taizhou Formation. (2) The migrating fraction of the crude oils located in internal slope belts is significant, which migrated along structural belts updip direction from southwest to northeast, was generated by the source rock of the 2nd Member(Ef2), Funing Formation, in the Chujialou deep subsag. (3) The Ef3 oil in the external slope and horst belt has lower maturity and higher concentration of pyrrolic nitrogen compounds, mainly migrated from northeast to southwest, is generated from lower mature source rocks in deep sag. （4） The oil accumulation models are different among three structural belts. In fault belts, the crude oil is accumulated in stepshaped fault block, and internal slope and horst belt are distributed by fault—lithologic reservoirs. The lower mature oils is accumulated in external slope’s horst and controlled by opposite directional fault.