The effects of different desertification stages (grasslands, fixed dunes, semi-fixed, mobile dunes) on soil bulk density, porosity, the contents and densities of organic carbon and total nitrogen, and the contents of ammonium nitrogen and nitrate nitrogen were studied in desert grassland located in north central Ningxia, China. The results showed that desertification of desert grassland had significant effects on soil physiochemical properties. As compared with grasslands, soil bulk densities of the fixed, semi-fixed and mobile dunes were increased by 0.3%, 2.9% and 2.4%, respectively. Soil porosity gradually decreased with increasing desertification stage. With the increase of soil depth, soil bulk density increased first, and then decreased under different desertification stages, but soil porosity first decreased and then increased. The contents of ammonium nitrogen, nitrate nitrogen, organic carbon and total nitrogen, and the densities of organic carbon and total nitrogen decreased gradually during the desertification process. As compared with grasslands, the contents of ammonium nitrogen and nitrate nitrogen, the contents and densities of organic carbon and total nitrogen in mobile dunes were increased by 27.4%, 31.8%, 44.8%, 56.7%, 43.5% and 55.7%, respectively. The above results suggested that desertification of desert grassland can deteriorate soil physiochemical properties.