The soil and water loss in the uncultivated slope land of fragmental soil,the cultivated slope land of fragmental soil and loess were observed and studied in Luanping central experiment area.The results shown that the amount of runoff and erosion each year in cultivated slope land of fragmental soil accounts for only 8 per cent and 1 per cent of that in loess respectively.It was poilted out that the main contoroled land for soil and water loss is the cultivated slope of loess in this area.