Abstract: Irrigation water requirements for Minqin county under several planting scenarios were calculated with the FAO-56 recommended method, to make an assessment of the water-saving potential of three measures which were proposed by Shiyang River Rehabilitation Plan under comparable conditions. The results indicated that with the same climatic conditions and traditional surface irrigation, the four main crops in Minqin County in 2006 required more irrigation water than in 1973 by 2.2×107 m3. Both adjustment of planting structure and expansion of planting area contributed positively to the water increase, while the former contributed more than 60%. If drip irrigation was adopted to corn and cotton in 2006, 5.5×107 m3 of water would be saved. The objectives of the rehabilitation plan were also evaluated in the paper. It is difficult to achieve the goal of saving water only by reducing farmland area. In contrast, water-saving irrigation technology has great potential in reducing irrigation water requirements.