Abstract: Through the Multibackstrip Software, the well spots which can reveal the movement strength of fault are selected as the places to study how structural subsidence velocity changed. Meanwhile, structural evolvement history on the seismic section are also analyzed in the study, according to backstripping the stratigraphy of interpreted seismic section. Combining both the above study results and fault distribution, it is studied how structure in Weixinan and Haizhong depression evolved. The research shows that there are two period of rifting and one period of depression during the Cenozoic, T₅ is the interface between the two riftings. And there are both contact and difference between the two depression.