The basic features of late-stage faults are studied based on the structure interpretations of seismic data and geometry and kinematics of fault system. The results indicate that in the Xijiang southern half-graben, the majority of the late-stage faults trend towards NWW-SEE direction under the tensional shear stress field, showing negative flower structure in seismic profile and structural styles including parallel style, cross style, echelon style, and feather style, etc. in the section. The late-stage faults mainly distribute in the south side of the half-graben. Based on the related research on trap forming, timing of hydrocarbon filling, and activities of late-stage faults, the late-stage fault system mainly plays three important roles in oil accumulation. They are fault controlling trap, namely, the late-stage faults control the formation and distribution of Neogene structural traps, the oil migration and spatial distribution dominated by the late stage faults, the good fault sealing abilities; and ultimate hydrocarbon accumulation in Neogene strata controlled by the lat-stage faults.