In order to further discuss the relationship between overpressure system in continental rifted basins and hydrocarbon accumulation, we take the Chexi area of Chezhen depression as an example. Based on definition of the distribution characteristic of overpressure system, we analyzed the overpressure system which has made an important contribution to hydrocarbon accumulation, such as influence on hydrocarbon expulsion, force of hydrocarbon migration and location of hydrocarbon accumulation. The result showed that,the overpressure system in Chexi area has three architectures, peripherally distributed and centering the generation center. The research of relationship between overpressure system and hydrocarbon accumulation showed that the overpressure system occurs as two hydrocarbon expulsion models, including internal overpressure stable hydrocarbon expulsion and convex overpressure episodic hydrocarbon expulsion. Overpressure is the main migration force for primary hydrocarbon migration and downward migration. In overpressure basins, the plane distribution and vertical collocation of overpressure control the dominant migratory direction and accumulation scale.Finally, the hydrocarbon accumulation model of overpressure source and centrifugal pump is established, and it is viewed that the favorable pressure collocation internal overpressure and the reasonable collocation between pressure-released region and available reservoir under overpressure are the potential areas for hydrocarbon accumulation. The research has not only deeply recognized the law of hydrocarbon accumulation in overpressure system in Chexi area of Chezhen depression, but also offered significance for petroleum exploration in other continental rifted basins.