The southern Sydney Basin is located in the southernmost part of the north-south trending Bowen-Gunnedah-Sydney Basin system, bordering the New England Fold Belt in the northeast and the Lachlan Fold Belt to the west. As such, the study area is generally considered to be part of a large foreland basin system within the Tasman Fold Belt of eastern Australia. Various studies have indicated that the southern Sydney Basin evolved from a back-arc extensional phase in the latest Carboniferous, through a passive thermal sag phase from the Early Permian to Middle Permian, to a typical foreland basin setting from the Late Permian to Middle Triassic characterized by tectonic stacking (from the east and northeast), flexural loading and increased compression. Tn back-arc Sydney Basin was intensely affected by back-arc spreading and trench subduction of the New England island arc, and developed serious earthquake and earthquake-related soft-sediment deformation. The soft-sediment deformation of Permian in the southern Sydney Basin consist of seismo-cracks, seismo-folds, fluidized veins, sandy volcano, load casts, flame structures, pillow structures, ball structures, pillow beds, slump structures and brecciation. The seismo-cracks and seismofolds are cracks and folds formed directly by oscillation of earthquake. The pillow beds formed by dehydration and sinking of the sandy beds during earthquake's oscillation. Fluidized veins and sandy volcano were made by instill into the seismo-fissures of the fluidized sands. The load casts, flame structures, pillow structures and ball structures were formed by sinking and instilling caused from oscillation of earthquake along the face between sandy and muddy beds. The slump structures and brecciation formed by gravity flow related to earthquake. The eismo-fissures, seismo-folds, fluidized veins, sandy volcano, load casts, flame structures, pillow structures, ball structures and pillow beds belong to the autochthonous seismites and slump structures and brecciation to allochthonous seismites.