Abstract: The slope-break belts are well developed in Middle Permian in Ke-Bai Area. Characterized by multiple orders along the source direction, they can be divided into basin-margin slope-break belts and inner-basin ones according to their respective natural geographical locations. Due to the persistent activities of boundary dominant thrusting faults and secondary faults in the basin, multiphased, episodic, differential activities and heritability are major features of the evolution of slope-break belts. Slopebreak belts play an important part in controlling stratigraphic overlapping, sequence architecture and distribution of sedimentary facies. In this paper, a reasonable model that slope-break belts control the formation of lithostratigraphic traps has been established. It is considered that the lithological traps, stratigraphic overlapping traps and unconformity surface-seal traps may be developed near the slope-break belts.