Abstract: Many late Jurassic to early Cretaceous rifted basins developed in deep Songliao Basin. The hydrocarbon enrichment degree of the basins varies a lot from each other. According to the research of more than 50 rifted basins, it is found that the different geological conditions result in the difference. The geological conditions include: the location of fault depressions in the basin, the difference in the structure of fault depressions, the activity intensity and periods of the controlling fractures, and the volcanism. Among them, the location of fault depressions in the basin and the difference in the structure are the most important. These rules can be important reference to the evaluation of the strategic area selection of peripheral fault depressions in deep Songliao Basin.

Key words: Songliao Basin, fault depression, fault structure, volcanic rocks, hydrocarbon-rich fault depression