Abstract: The Zengmu Basin and Brunei-Shaba Basin of Southern South China Sea are rich in oil and gas resources. A large amount of oil and gas fields and structures have been found there. Facts show that the characteristics of hydrocarbon generation, migration and accumulation are closely related with the Borneo Block to the Southern Zengmu Basin and Brunei-Shaba Basin. The geology of the Borneo Block is complex. The ancient South China Sea disappeared gradually in Paleocene, and collided with the Borneo Block. The Borneo Block uplifted in Miocene. In such geological conditions, the Rajang River and Baram River in the Borneo Block were the major sources to supply sediments to the southern Zengmu Basin and Brunei-Shaba Basin. Deltas, coastal deposits, turbidite fans, and shallow marine sandstone reservoirs were developed. At the same time, the compression and twisting type of structures were widely developed. They provided not only the formation conditions for the fault block and anticline types of reservoir, but also the conditions for oil and gas migration.