Abstract: On the basis of the main achievements about the investigation of soil and water conservation, the strategy and the new thinking for the improvement of ecoenvironment on Loess Plateau were expounded, especially soil and water conservation, by molecular biology and biotechnology was expounded. On the basis of which the soil and water conservation engineering and eco-environmental improvement on Loss Plateau by the way of biological means of vegetation will have a clear and decided aim. The former related studies, mainly from the angle of the outside circumstance (outside factor) are lacking in clear aims and difficult to instruct sustainable utilization of the resources. The current situation of this field has fully implied this point. Although there are some problems remained to be deeply investigated and probably, a long way to go. The complete resolution to the soil and water conservation problem on Loess Plateau of China is dependent upon molecular biology and biotechnology.