Abstract: The authers conducted field investigation and research work in the Salawusu River Area in 1978, and have divided again the strata of the Salawusu River, adding two groups, namely, Chengchuan Gronp and Dishaogouwn Group. It is suggested that the clmate was mild and wet, there were numerous rivers and lakes, animals and Plants were thrifty in the study area at the early stage of the Late Pleistocene. The climate became dry and cold and eolian sand accumulated at the later stage of the Late pleistocene; the climate became once more mild and wet at the early stage of the Holoccne, lake are marsh sediments and Heilu soil was formed. After that the climate turned to be dry and cold again and thus the semi-arid steppe landscape was formed. These changes were caused by the climatic fluctuations of the glacial age and interglacial age of the North Hemisphere. In the study, it is sugested furfher that Mu Us Sandy Land underwent a series of vicissitude processes, e. g. formation and encroachment of shifting sands, fixation and reduction of dunes. How to rehabilite the desertified land well in the study area? An attention must be paid on the following two aspects:(1) to change the current irrational human activities;(2) to inderstand and-master, further the natural environments, especially the principles of climatic changes. The writers describe in the paper that the human activities must be guided adroitly according to local environment in order to meet the needs of production and construction.