Soft sediment deformation Structure is named syndepositional deformation structure, and the developmental feature, distribution rule and depositional model are important for the research of reservoir. After the observation of the core in the work area, we found the microfault, liquid dike, liquid twist deformation, ellipsoidal structure, autoclastic breccia, and so on. And we analyzed the stress environment and characteristic of the soft sediment deformation structures. By the analysis of the distribution of the soft sediment deformation structures, the developmental frequency and gradation are related with the angle of dip of the Zhen② fault and Hanliu fault, the distribution of the soft sediment deformation structures is controlled by the ancient landform. The physical property and communication of the reservoir are changed by the soft sediment deformation structures. On the base of the depositional model of the soft sediment deformation structures by predecessors, we set up the new depositional model of the soft sediment deformation structures of Gaoyou Sag, the soft sediment deformation structures of work area are mainly developed near the ramp region of boundary fault, and it is departed into 3 parts, the upper shallow water region, middle ramp region, bottom deep water region.