Abstract: According to synthetical analysis on geometry and drilling holes and seismic data in the Jiyang Depression, the authors obtained some new recognition on the structural styles of basin. Three basic styles of extensional-type, strike-slip-type and inversion-type were proposed in the paper. Of them, the extensional-type structural style is the most important one in the studied area and was describled in detail. From geometry and forming mechanism, five secondary styles of the extensional-type structural style, including tilted faulted-block, slide faulted-ramp, buried hill draping, gravitative antiform and diapir, were reported. There exists a close connection between the type of secondary structural style and the location of geological body in the depression： the tilted faulted-block style is developed mainly in the gentle slope zone of depression, the slide faulted-ramp style is mainly distributed in the steep zone, the diapir-type structure occurs in the depression zone, the buried hill draping style is developed in the uplifting areas around basin and the buried hill zone of depression, and the gravitical antiform was formed in the down-sliding side of main fault. Results suggest that with the thicken deposit of basin, gravitical working becomes more and more important in generation of structural styles. Under the strike-slip shearing of the Tan-Lu fault zone, a lot of en echelon and brush structures were formed in the eastern part of the Jiyang Depression. Owing to transformation of regional tectonic settings, a transformation of stress field from compression to extension took place in the studied area during the early Late Cretaceous, producing a series of negative inversion structures in the basins and the stress field became weaker and weaker from the east to the west. Thus, the strikeslip structural style is resulted from strong shearing of the Tan-Lu fault zone, and the inversion structural style is caused by transformation of regional tectonic settings.