To clarify the Paleogene tectonic characteristics of the Dongpu Sag and the difference from those of other depressions in the Bohai Bay Basin，we conducted the tectonic analysis of the Dongpu Sag with seismic，drilling，well logging，gravity and magnetic data and studied the controlling effect of tectonic evolution on hydrocarbon accumulation with crude oil samples and related laboratory data. The results show that the Paleogene basin in the Dongpu Sag is a Phase 2 fracture basin developed at 51 Ma with deep sedimentation（6 400 m）and a high rate（246 m/Ma）. Influenced by NE fault cutting and frequent tectonic transition，the basin exhibits strong heterogeneity and drastic lateral change and enables the development of many uplifts and sags，laying the tectonic groundwork for the composite petroleum system. According to the distribution of effective source rocks，paleotectonic ridges during hydrocarbon accumulation，fluid differences，and other factors，the Dongpu Sag can be divided into 10 petroleum systems featured by near-source hydrocarbon accumulation. The forward structure of the Dongpu Sag has a large tectonic scale，high amplitude，and a steep slope，and is effectively arranged with the source-reservoir-cap assemblage，which is conducive to the migration and accumulation of oil and gas towards the high part of the structure and controls the distribution and enrichment of oil and gas. Through the methods of volume conservation，comprehensive formation thickness trend，comparison in adjacent thickness，and vitrinite reflectance，we think that denudation of the Dongying Formation in the Dongpu Sag is 200-800 m on the whole. The Paleogene formation is continuously deep buried and stably preserved，and the Dongpu Sag is a weakly transformed basin with the composite petroleum system，which is featured by near-source hydrocarbon accumulation as well as rich and continuous accumulation controlled by the forward structure.