Abstract: As an important crude oil exploration and production area in the western South China Sea, Beibuwan Basin has the advantages of oil enrichment in multiple sags, hydrocarbon accumulation in multiple strata and multiple models. In recent years, breakthroughs have been made in new fields and new types of oil-gas exploration involving shale oil, buried hills, lithologic reservoir, deep hydrocarbon resources, and backup sags/subsags. The paper investigates the regional petroleum geological conditions, so as to make clear the regional hydrocarbon accumulation regularities of the important hydrocarbon-generating sags in Beibuwan Basin, and guide the subsequent fine exploration and development of conventional oil-gas and the new fields and new types of hydrocarbon exploration. The research shows that the multi-stage tectonic movement controlled the tectonic evolution and material filling in Beibuwan Basin. The oil shale and semi-deep lacustrine mudstone of Member 2 of the Paleogene Eocene Liushagang Formation are the most important source rocks in the basin, several sets of source rocks are developed in Member 1 and 3 of Liushagang Formation and Member 2 of Weizhou Formation, and buried-hill reservoir and clastic rock reservoir are also developed, thus forming a multi-source, multi-reservoir and multi-cap pattern. The hydrocarbon accumulation in multiple sags of Beibuwan Basin is controlled by multiple mechanisms, such as near-source primary hydrocarbon accumulation in sag, vertical accumulation in fault belt, fault-uplift belt and steep slope belt, bypass accumulation in slope area, as well as converged accumulation pattern in salient and uplift. Oil and gas are orderly distributed in multi-sags and multi-zones. The oil-gas differential accumulation controls the distribution of internal gas and external oil, deep gas and shallow oil. Moreover, there is a significant difference in the types of oil-gas reservoirs in different zones. Under the guidance of regional petroleum geological conditions and accumulation regularities, the comprehensive analysis of resource potentials, accumulation conditions and exploration and development degree indicate that shale oil, buried-hill, lithologic trap, deep hydrocarbon resources and backup sags/subsags are important new types and new fields for future exploration and development in Beibuwan Basin.