According to the principle of complementary relationships existing between living things and climate, using the method of quadratic programing pattern, we use sowing area of plant and optimum yield as the bound condition, the minimum varance of the total yield as the objective founction stimylate the optimum result at mico-computer and main-frame computer. This optimum result shows the optimal growing ratio of several crops in one area or one kind of crop at various areas in a large scale region,with this, we reach the goal of disaster-resistance, disaster-reduction, stable yield, highyield, and high-effect.