Abstract: From an analysis of the Permian-Triassic sedimentary features the paper discusses the de-positional environment and history of sedimentary and tectonic evolution during the Permian- Triassic in the south Qilian area. These features indicate that the area belonged to a relativelystable pericontinental sea in the Permian-Triassic. The sedimentary evolution progressedthrough two major transgressive and regressive cycles and the sedimentation and distribution offacies zones were mainly controlled by the Jun UI Mountain-Nanshan Mountain fauIt to itssouth and sea level fluctuation.