By the methodology of ? The T emporal for The Spatial?, the changes of soil physical and chemical properties on the southeastern edge of Mu Us sandy land were studied. Results showed that soil physical and chemical properties changed regularly in the process of desertification. With the increased degree of desertif- ication, the contents of soil clay, soil water, organic matter, organic carbon, and total nitrogen decreased,while the content of soil sand, soil bulk density, and C/ N increased. With the increased depth, the content of soil water and soil bulk density increased and the contents of organic matter, organic carbon, and total n- i trogen decreased, while C/ N increased firstly and decreased later. Results of correlation analysis showed that the correlations of soil bulk density or C/ N ratio with other indicators were negative, while the correlations of other indicators were positive. T he negative correlations of soil bulk density with the content of organic matter and total nitrogen were significant at the level of P< 0.01 and so was the positive correlation between the content of organic matter and total nitrogen. T he correlations of the content of soil clay with soil water, soil bulk density, the content of organic matter, and total nitrogen were significant at the level of P< 0. 05 and so were the correlations of soil water with soil bulk density, the content of organic matter, and total n- itrogen. Soil quality was reduced and there were close correlations in soil physical and chemical properties in the process of desertification.