Abstract: In the typical arid desert area and the sandy loamy soil,irrigating standard could be lowered even if the soil moisture was always kept on less than 40% of field water capacity.If so, the seed yield of wheat would not remarkably decrease. When the amount of water that infiltrated into deep soil layer could not be used by wheat,then yield of wheat would be significantly reduced.The amount of water infiltrated,evaporated and used by wheat have not obviously differed in each fertilizing treatment while the total efficicnt amount of N,P and K was less than 800kg/hm²,but the seed yield increased as the increase of fertilizing amount.When the ratio of efficient fertilizer and irrigating water was 0.12kg/m³,seed yield was near 5500kg/hm² and productive efficiency of water was 0.74kg/m³.It is necessary to reduce irrigating standard and increase the fertilizer in order to enhance the seed yield and productive efficiency of water.