Based on the drill and seismic data and the organic geochemical analysis data of the source rocks，the geochemi?thinner from centre to outsides. In Bozhong sag，the distribution of high-quality source rocks controls oil and gas distribu? tion and the slope areas near the depression center are the favorable exploration targets. cal characteristics of Paleogene source rocks in Bozhong sag have been studied from several aspects such as organic abun? dance and types，maturity，sedimentary environment，original source of rock and biological markers，etc. The area，where the high-quality source rocks developed，has been pointed out. And then the forming conditions and distribution of the high-quality source rocks have been described. On this basis，all the relationships between high-quality source rocks and hydrocarbon reservoirs have been analyzed to reveal the exploration potential in Bozhong sag. The studied results show that there are three sets of hydrocarbon source rocks developing respectively in the third member of Shahejie Formation，the sec? ond member and the first member of Shahejie Formation，and Dongying Formation. The source rocks have high quality， good types and great potential for hydrocarbon generation and expulsion. The types of source rocks in the third member of Shahejie Formation are mainlyⅠandⅡ1，and the rocks have the highest abundance of organic matter and are in the thresh? old of hydrocarbon generation with the highest quality. It is found that the main conditions for high-quality rocks generation are high rate of biological generation，good source material and good preservation conditions through analyzing forming con? ditions of the three sets of hydrocarbon source rocks from the aspects of source material and sedimentary environment. Then the spatial and temporal distribution characteristics were summarized. The high-quality source rocks generation is con? trolled by sedimentary environment and centre，where semi-deep lake or deep lake developed and the source rocks became