Abstract: No breakthrough has been made so far in the Hepu Basin, the northern margin of the South China Sea, for oil and gas exploration, due to lack of in-depth understanding of geological conditions for petroleum accumulation. Major hydrocarbon source rocks in the basin are low matured dark mudstone series in the center of an Eocene deep lake, and its characteristics and geological conditions for accumulation of the low matured oil and gas from immature source rocks are similar to those in the Baise Basin. In this paper, in-depth analysis of the abundance, type and maturity of organic matters of the low matured source rocks in the Hepu basin is made, focusing on comparison with the analogy of the Baise Basin. It is concluded that the Paleogene hydrocarbon source rocks in the Hepu Basin have favorable geological conditions for generation of low mature oil and gas/bio-gas. Therefore, we can learn from the case in the Baise Basin, which has earned successful experience in exploration of law matured oil and gas/bio-gas, to establish the exploration direction and strategy for low maturity oil and gas and biogas resources in the Hepu Basin.