The Zhengyang Basin in Qianjiang, Chongqing is located in the wide spaced folds among the southeastern Sichuan, Chongqing and northwestern Hunan Provinces. The Late Cretaceous Zhengyang Formation that developed in the Zhengyang Basin is composed of two Members. The first Member is featured by alluvial and diluvial conglomerates, and the second Member is featured by fluvial and lacustrine sandstones and siltstones, in which abundant dinosaur fossils were discovered. The basin is an intermountain basin formed the wide spaced fold belt since the Yanshanian Movement, investigation on the tectonic and sedimentary evolution of this basin is crucial for studying the Cretaceous regional tectonics in the surrounding areas, however, detailed studies on this basin are lacking. We performed studies on the sedimentary sources and tectonic evolution of the basin is of great significance, to reveal the Late Cretaceous tectonic evolution of southeastern Sichuan, as well as the living environment, death and mass burial mechanism of the contemporary dinosaur fauna.Methods: Based on observation, measurements and analyses on the sedimentary sources and structural characteristics of the Zhengyang Formation, we reevaluated the boundary fault, paleocurrent direction, sediment source and tectonic evolution of the basin. Results:The sedimentary source of the Zhengyang Formation mainly came from the west. The Apengjiang fault controlled development of the Zhengyang Basin and deposition of the Zhengyang Formation.Conclusions:The remote effect of the Yanshanian subduction of the paleo- Pacific plate formed widely- distributed joints and thrust faults in South China. Due to the continuous stress, these faults connected the detachment layers, thus the rock units stacked near the fault slope, and the anticlines spreaded and then gradually formed the wide spaced folds. In the late Yanshannian period, the normal fault "Apengjiang Fault" developed in this area with the retreat of the Pacific plate, which controlled the formation of the Zhengyang Basin with fault in the east and lapout in the west of the basin. The terrane on the west of the basin provided source materials. In the Himalayan period, this area was uplifted by local compression and denudation took place.