This study is based on the characteristics of nat ure, society, and economy of Wuqi County, Shaanxi Province.Through frequency analysis and expert consultation, the evaluation index system of ecoenvironment quality for Wuqi County is stablished and the weight of each index is calculated by using the met hod of analytic hierarchy process(A HP).Af ter eliminating the dimension influence, the eccγenvironment qualit y index for Wuqi Count y from 1995 to 2004 is calculated.In view of the nat ural eco-environment, social eco-environment, and economic eco-environment, the va riation of eco-environmental quality of Wuqi county in the past ten years is qualitatively evaluated and quantitatively analyzed.The research work provides a reference for sustaina ble development of Wuqi County and the Loess Plateau.