Abstract: This article elaborates the petroleum characteristics and reservoir types of the Paleogene-Neogene half graben-like rifts in the eastern part of China mainly in terms of six aspects-fault system, types of structural trap, distributed formations, contact relations, types of sand body, and basement. Deep sag belt is elaborated not only as sourcing area but also as reservoir area. Based on the analysis, rift basin is divided into single-rift type and dual-rift type. Each single-rift depression can be divided into three secondary structural units-steep slope belt, deep sag belt and gentle slope belt. The article focuses on the development conditions and distribution laws for various subtle oil and gas reservoirs in deep sag belts where there are no l