Objectives: Soft- sediment deformation structures have been identified in Gushan Group of Cambrian of lower Palaeozoic in Bohai Sea area for the first time. Methods: Based on the detailed observation and description of drilling cores, typical sedimentary structures including liquefied diapir structure, liquefied carbonate volcano, liquefied micritevein, liquefied breccias and step microfaults have been observed. Results: There are liquefied diapir structure——liquefied micritevein belt, liquefied breccias zone and step microfaults belt from bottom to top in vertical profile of the both stages according to the brittle and plastic deformation characteristics. Conclusions: The seismites of this formation may be account for the activities of ancient Tanlu fault zone in Cambrian, and is also the response of the splitting of the SinoKorean plate which cracked into North China plate and Jiaoliao plate.