Abstract: In order to identify the appropriate water and fertilizer doses for drip irrigation grape in an extreme arid area,the optimal water and fertilizer doses with higher yield and better efficiency were evaluated comprehensively for a mature seedless white grape in a test field by using the principal component analysis method. Two factors of irrigation and fertilization were selected with four levels 6 000（ W1）,6 750（ W2）,7 500（ W3）,8 250 m3/hm2（ W4） for irrigation dose,three levels 450（ F1）,750（ F2）,1 050 kg/hm2（ F3） for fertilization dose. The results show that effects of water and fertilizer interaction on yield,water and fertilizer utilization efficiency and quality of drip irrigation grape have statistical significance（ P＜0.01）. The influence of irrigation and fertilizer doses on titratable acid is also with statistical significance（ P＜0.05）. The influences on grape yield,water use efficiency,fertilizer partial productivity,soluble solids,and vitamin C are statistically significant（ P＜0.01）. The maximum yield occurs in treatment W3 F2,especially with a 29.76% increment compared with the minimum yield treatment. The highest soluble solid content is achieved in treatment W3 F2. The richest titratable acid is reached in treatment W4 F2,unfortunately,the difference from treatment W3 F2 is not statistically significant（ P＞0.05）. The vitamin C quantity per 100 g is 7.37-8.52 mg across different water and fertilizer treatments,and the difference between treatment W3 F2 and W4 F3 is not statistically significant（ P＞0.05）. The quality index is better in treatment W3 F2. The results of principal component analysis show that the best water and fertilizer treatment for the drip irrigation grape in the extreme arid area is W3F2 in which N,P₂O₅ and K₂ O are 300,150 and 300 kg/hm2,respectively.