There were obvious differences between the southwestern and the northwestern Ordos basin in the Late Triassic. The northwestern part developed rift basin, and the southwestern part developed foreland basin. The rift basin, controlled by Helanshan extensional normal faults, was linked with Alax compressive structural belt The foreland basin was linked with East Oilian fold thrust belt, the thrusting of which controlled the subsidence and the deposition of the basin. The stratigraphy of the two kinds of basins is divided into three sequences which are constituted饰various depositional systemsandshow different property of episodic tectonism. Inthe southwestern Ordos foreland basin, Sequence 1, Sequence 2 and Sequence 3 mainly composed of steep-sloped delta system, alluvial fan system and river system, were the depositional responses to the two times of thrust loading of East Oilian fold thrust belt and the isolated balanced subsidence after thrusting respectively, and the tmsin subsidence historycurve is represented by a two-segment convex-upward pattern. In the northwestern Ordos rift basin, the three sequences, consisting of alluvial fair braided channel plain systen and fan delta system, were the depositio}al responses to the three times of rift subsidence, and the subsidence history curve is of concave-upward pattern. The Late Triassic basins and the basin marginal strncturalbelts are arranged specially in anunconstrainedlateralextrusion, constituted by East Oilian indenter, Alax compressive wedge, Helanshan lateral margin and Sino-Mongolia buttress, which controlled the processes of tectonism and basining in the study area, and determined the differences of basin property between the southwestern and the northwestern Ordos basin. The regional study shows that the formation of the lateral extrusion is the result of the close subduction of Paleo-Tethys Domain and the passive confinement of Angarachstan Domain.