The main factors influencing development of agricultural economy in experimental area of soil and water conservation in Ansai county are population, soil and water conservation level, land area of agriculture, forertry,animal husbandry, and income from sideline occupations, etc. The total value of production each will increase steadily at the annual rate of 4.2% during 1986-2001,as GM (1, 1) forecasted, and is directly related to population, income from sideline accupation forest land area, soil and water conservation level,and animal husbandry land area，but negatively related to agricultural land area, as the analysis of the relativity shows. To maximize the total value of production of agricultural economy or the total average value of production each in the experimental areas, the productive forces must be improved, condition of sideline occupation be developed greatly, forest land area must not be less than 3000 of whole arable land，the agricultural land area should be about 25% of whole arable land, so as to optimize the production structure of agriculture, forest, animal husbandry,sidqline etc,