The ecological condition of agriculture in the west of China is extremely fragile and there exists the potential of a series of problems,such as severe desertification,environmental degradation.Meanwhile,its social and economic basis is relatively weak,especially in the typical agricultural regions.How can we not only realize agricultural industrialization and agricultural specialization in the fragile regions,but also combat the environmental problems in the process of their agricultural production,then develop sustainable economic system in local regions?芽It is necessary to make the functional regionalization of agricultural resources and environment ahead of schedule.Based on the sustainable idea and the eco-economical-system theory,this paper explores indexes of the agricultural-functional regionalization in Yanchi County,which is a typical agricultural county in central Ningxia Hui Autonomous Region.The paper combines mathematics-ecology models with clustering analysis models of statistics to make the agricultural-functional regionalization of the county.On the basis of physiographical regionalization,it adds the principal components analysis of social and economic indexes,which come from the analytic function models of SPSS and include four typical elements reflecting the standard of agricultural production profit,the population pressure,the population increasing rate and the standard of non-agriculture of each village respectively.The final result of agricultural-functional regionalization includes five agricultural-functional sub-regions: 1) the grain-economic-crop-wood-stockbreeding-medicine eco-economic region in the upland of northern part of the county,which consists of five villages,and its function should be focused on developing byproducts to meet the demand of good market condition while preventing desertification;2) the stockbreeding-wood-grassland-grain eco-economic region in sandy upland and bottom land,which consists of four villages,and its function should be focused on raising sheep while seeding degenerated pasture;3) the grain-oil-economic crop-stockbreeding-special local product region in the sandy bottomland which consists of two villages,and its function should be focused on developing special local farm products of food and oil plants while paying more attention to local salina;4) the grain-economic crop-fruit-vegetable-stockbreeding region in the upland and bottom land of Dashuikeng town,and its function should be focused on the economic product,such as fruit and vegetables while protecting drainage area in the south;and 5) the grain-oil-special local product-fruit-stockbreeding region in the upland and low mountain area which consists of four villages,and its function should be focused on planting oil plants and pasture of high quality while conserving soil and water in the loess upland.Through analyzing eco-economic characteristics of these regions,the paper proposes the sustainable development strategy for each region.