Based on the analysis of hydrological data,planting structure and water-saving technology development in Manas River Valley in Xinjiang,the potential of the available agricultu-ral water resources in the future was quantitatively estimated by considering surface water-saving and groundwater exploitation potential.It was considered that the main approach about increasing agricultural water resource was to reduce the waste of surface water in this region according to actual situation of water resources use.The results also showed that the ultimate utilization volume of agricultural water resources in the future can reach 10.75×10⁸m³.The potential of the available agricultural water resources would reach 2.13×10⁸m³ in 2010,of which groundwater and surface water exploitation potential was equivalent to 0.40×10⁸m³ and 1.73×10⁸m³ respectively,which accounted for 18.8% and 81.2% of the total agricultural water resources potential.In 2010～2030,the potential of the available agricultural water resources would equal to 5.33×10⁸m³,which was composed of 1.12×10⁸m³ of groundwater exploitation volume and 4.21×10⁸m³ of surface water-saving,which accounted for 21.0% and 79.0% of the total water-saving potential respectively.This study conclusion can be applied to agriculture water resources exploitation and water-saving planning,which is also very important to realize the rational allocation of water resources and the sustainable development of economy.