The geological structure characteristic of Red River fault zone after entering South China Sea is one bottleneck in research. Based on the geometry and kinematics features of Red River fault zone among the Yinggehai area and tectonic interpretation of aerial gravity anomaly and seismic profiles, this study obtained the chronological data of Red River fault zone combined with the depocenter migration regulation of Yinggehai Basin. The Red River fault zone divaricates nearby the entrance of South China Sea. The The Tien Lang fault, one of the branches, converts into NE direction with the horsetail form. The Red River fault zone divaricates into four branches among the Yinggehai Basin, here named A(No.I Fault), B, C and D(Ying Xi Fault). All of these 4 branches strike into NW—SE with the extension length ranging from 420 to 500 km. The typical flower structure in the seismic profiles and the horsetail form of Tien Lang fault jointly indicate that the Red River fault zone is characterized by strike slip movement. The Red River fault zone controls sedimentation of Yinggehai Basin. Change regulation of depocenter migration of the Yinggehai basin reveals that the fault was sinistral strike slip during 30～15.5 Ma, transformed to dextral strike slip during 15.5～5.5Ma, and resumed to dextral strike slip since 5.5Ma.