Abstract: Diapiric structure is an important type of oil and gas traps. Whether such traps actually exist in east China and how is the mechanism of their formation is a subject of much dispute. Based on the study of the oil-bearing structural features in the deep and shallow levels in the Dongying depression in east China, the authors present the following observations which may shed some light on the subject. 1. Diapiric structures of plastic salt and gypsum and plastic soft clay of different origin are widespread in the Dongying depression. 2. The plastic rocks that form the core of the diapiric structures are ridge-like, arranged en echelon along the regional trend.Three such diapiric structural zones trending NEE have been noticed. 3. In the various diapiric structures, there are graben-like fault systems of varying complexities developed on the crest of the structures, typical of diapirism and indicative of the occurrence of uplifting of plastic rocks. 4. The distribution of diapiric structures in the Dongying depression is controlled by the broom-like tectonic system in the Bohai Bay. They are the product of both gravity and horizontal torsional stress. 5. The basic features of the diapiric structures in the Dongying depression are characteristic of the oil basins in east China, where plastic rocks of salt, gypsum and clay are well developed in the upper part of Eocene and the lower part of Oligocene and their deformation has a great influence on the evolution of Cenozoic structures and the formation of oil and gas traps there.