Various types of inversion structures developed in the southwest Bohai sea in the pre- Cenozoic,which has great significance for the tectonic evolution of Mesozoic. Based on the drilling and 3D seismic data, the characteristic of the inversion structure in the study area is summarized and the genetic mechanism is discussed. The result shows that ①two phases of inversion tectonics have been identified which are negative inversion structure and positive reversal anticline.The negative inversion structures are mainly negative inversion fault, which can be devided into long- term active inversion fault and short- term active inversion fault according to the activity of the fault in Cenozoic, ②the scale of the early faults and the support of the rigid basement control the difference of the activity and the trend of the inversion fault, and the the reverse anticline is the dominant positive reverse structure, ③The two- phase inversion is a good record of the Yanshan Movement in the research area. Negative inversion structure recorded the process of the post- tectonic curtain lithosphere collapse during the Ⅰ and Ⅱ phase of Yanshan Movement, and the positive inversion structure is the sustained response of the NW- trending subduction of Pacific plate to the curtain during the Ⅲ phase of Yanshan Movement.