As the control effect of the distribution of excellent hydrocarbon source rocks on hydrocarbon accumulation, it is of great importance to identify it for Chinese offshore hydrocarbon exploration, which is very difficult because of hard drill-coring. The method of evaluating hydrocarbon source rocks by logging data has been built and better applied in continental Jiyang Depression in Bohaiwan Basin and Qaidam Basin. It can be also used in offshore basins as they have the similar geological characteristics. As we know, hydrocarbon source rocks are quite heterogeneous in offshore basins such as East China Sea, Pearl River Mouth, Yinggehai and Bohai basins, so locating better source rocks among dark mud shale with large thickness and wide distribution will effectively improve the success rate of offshore hydrocarbon exploration.