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, referring to results of structural study and oil source comparison, petroleum migration and accumulation of the Qintong sag, northern Jiangsu Basin, are discussed in this paper. The results are as follows: 1) the pyrrolic nitrogen compounds of crude oils in different structural belts reveal significant; 2) the migrating fraction of the crude oils located in internal slope belts is significance; 3) the Ef3 oil in the external slope and horst belt has lower maturity and higher concentration of pyrrolic nitrogen compounds is generated from lower mature source rocks in deep sag; and 4) the oil accumulation models are different among three structural belts.