Abstract: In order to make an objective evaluation of the hydrocarbon resource potential in the Bodong Sag based on stratigraphy, tectonics and sedimentology, as well as organic geochemitry of rock and oil samples, the authors systematically studied the characteristics of source rocks, oil and gas sources, distribution of high-quality source rocks and thermal evolution of source rocks in the sag. And the resource potential of this sag is assessed using basin simulation technology. The research shows that four sets of source rocks are well developed in the sag, and the source rocks of E₂S₃ and E₂S₃ are the best and the E₂S₄ and E₃d₃ fall within the middle-good level. Crude oil found in the sag can be divided into four source types and each type is distributed in definite area. Among the four types, oil from E₂S₃ dominates. Among the 4 sub-sags in the Bodong Sag, west Bodong sub-sag and the north Miaoxi sub-sag are the two top potential hydrocarbon-rich sub-sags, which have more sets of high quality hydrocarbon source rocks and larger hydrocarbon generation potential.