The characteristics and mechanism of soil degradation were analyzed, as the case study of Da'an city and Changling county in the west part of Jilin province. Soil degradation in this region mainly expressed decrease of nutrition element and increase of salt and alkali. Soil degradation had been caused by natural factors and human impacts. Natural factors were potential and human activity was to enhance potential soil degradation. With application of GIS and SPSS, it was analyzed that dynamical change and horizontal and vertical distribution of chemical elements. Soil horizon structure was complex. Soil salt content in soil profile expressed T shape, straight trape-zoid, reverse trapezoid, and column shape.