Maize is a high—yielding and vast—adaptive crop. As population increases, the demand for grain has been stimulating more and more cultivation of maize, which cer tainly has resulted in the continuous cropping of the crop. After years of investigation, it was found that continuous cropping of maize did not cause a decrease of grain yield in maize and that the soil fertility was not deteriated from continuous cropping of maize, because the stubbles and stalks could be returned to the field. Therefore, full use should be made of the positive effect of maize in the agroecological system and efforts be made on soil conservation and improved cultural practices, to increase grain yield of maize per unit area.