Abstract: Analytical results of grain size and magnetic susceptibility performed on samples from the west wall of the T911 at Zhangjiawan site show that climate evolution, to a certain degree, is under influence of the changes of the southwest mosoon Development of the agriculture and handicraft industry made an excessive exploitation of the vegetation resources and the ill consequences of the human activities made the ecological environment in the study area deteriorate and finally made the civilization collapse Archaeological excavation shows that the study area was a developed economic center with flourished, handicraft industry and agriculture at that time As a result of the blind exploitation of the natural resources, the ecological environment was deteriorated Without protection of the vegetation, the detrital materials on the sloping land provide conditions for landslides and erosion, leading to decline of local civilization The eco environmental evolution of this area is thus controlled by human activities and also changes of the strength of the south west mosoon Huge mountain ranges surround the study area from north west and south east respectively, and the geomorphologic features make the area unique both climatically and ecologically The mode of the environmental evolution is distinctive from any other regions.

Key words: Zhangjiawan site, palaeo environmental evolution, Wushan, Chongqing city