Abstract: Based on the study of physical characteristics of Jinyang Basin, through comprehensive processing of gravity and seismic data, the paper analyzes the characteristics and causes of gravity field and classifies the fault system. The gravity field represents the joint action of western sag, mid-eastern uplift and mid-southern sag in the area. The regional gravity field is mainly caused by the undulation of pre-Mesozoic bottom (basement), while the high-low alternating distribution of residual gravity field reflects the concave-uplift pattern and developed faults inside. The structural system is mainly composed of NE- and NW-trending faults, with the former formed earlier than the latter, both multiply reforming the secondary structures of Jinyang Basin in later stages, and forming the concave-convex alternating structural pattern.