Abstract: The western segment of the Qilian Mountains is situated on the northwestern margin of the Qinghai-Xizang Plateau. The environmental changes since the Pleistocene represent the environmental responses to the uplift of the Plateau. In the light of CaCO₃ contents, paleomagnetic and sporopollen data, twelve climatic stages of cold and warm have been established, respectively for the study area. In addition, at least three phases of the accelerated uplifting of the Plateau are recognized:the early Early Pleistocene, early Middle Pleistocene-late Early Pleistocene and Late Pleistocene-Holocene.