The scale of agricultural development of the arid area depends on the carrying ca-pacity of water resources,Taking Hexi Corridor as an example,this paper sets up an evaluation model by applying the fuzzy synthetic evaluation method.The results showed that the develop-ment of water resources in Hexi Corridor tended to reach saturation capacity.Therefore,to de-velop water-saving irrigation,raise utilization factor of canal system and improve water use effi-ciency are the fundamental way out for assuring and developing agriculture in arid area.