The valuation of ecosystem services has become one of the key elements and the focuses of sustainable development. Minle County of Ganshu Province located in the middle reaches of Heihe River, water shortage and land use / cover change have dramatic and unique regional characteristics. Based on GIS, according to the method of calculating the value of ecosystem services by Costanza and the Chinese terrestrial ecosystem service value per unit area tables, the land use change, ecosystem service value and ecological risk index in the study area during 1996-2009 were analyzed. The results showed that: 1) Land use pattern had changed dramatically from 1996 to 2009. Farmland, woodland and grassland land change were the focus of the study area. The general tendency was that the areas of farmland, grassland and unused land decreased, while the area of the woodland and the construction land significantly increased. This change had a direct impact on the eco-changes in service value. 2) The ecosystem service value across the study area reduced by 12.01% over the past 13 years. The ecosystem service value which provided by Minle in 2009 was still kept on maintaining soil formation and protection as major pattern, biodiversity protection, waste treatment, gas regulation, water supply and climate regulation were relatively weak. 3) The sensitivity analysis showed that the ecosystem service value (ESV) lacked of flexibility, indicating that the results of ecosystem service value evaluation were reliable. 4) Research results from study on ecosystem service value and ecological risk index proved it credible that the environment here was improved from 1996 to 2009.