By observing and analyzing of the sedimentary facies of about ten Cenozoic profiles in the central and southern Ningxia region, we suggest that the distribution of these strata had close relationship with the development of the Qinghai-Tibetan Plateau, which showed the whole process of a flexural basin from its birth to death resulting from the continuous compression of the Indian Plate. During some periods after the collision between the Indian Plate and Eurasian Plate (30~40 Ma), the collisional effect had shown in the Nanshan Corridor, a thrust belt and its flexural basin took form, and on the forebulge of this basin many normal faults developed. It is these normal faults that controlled the distribution of the Sikouzi Formation. The deposition of the Qingshuiying Formation occurred during the weakening stage of thrusting along the Nanshan Corridor. The whole basin changed from an underfilled basin to an overfilled one, and the deposition system also changed accordingly. During the deposition of the Hongliugou Formation, tectonism became more active, which resulted in the uplift of the Xiangshan area and other in the basin, earlier basins were disassembled, and some piggy-back basins took form. Tectonism from the end of the Pliocene to Pleistocene was the strongest one affecting this region, which led to the further disassembly of earlier basins, large-scale thrusting occurred in the basin and earlier basins were included into the thrust wedge of the northeastern margin of the Qinghai-Tibetan Plateau.