The field experiments for rotation of grass-crop and belt intercropping have been taken inExperimental Station of Soil and Water Conservation of Heligeer in Inner Mongolia. Three kindsof grasses, i. e., Vicia sativa L,Melilotus suaveolens Ledeb,Vicia villosa Roth which have grownfor two years,were rotated and intercropped with the local major crops. The results show that therotation of grass-crop and belt intercropping are not only an important way to recover fertility,to rich soil and to increase yield of crops and grass,but also a scientific planting system that con-servates soil and water,and utilizes and protects land because of the remarkable benefits of soiland water conservation.