In particular fertilization level (N225kg/hm2‚P150kg/hm2)‚the effects of N‚P fertilizers on the height‚ yield‚stem/leaves and the coefficient of yield variation of individual species of three-year old alfalfa/smooth bromegrass mixture sward in Oasis under different planting ratio (5:5､6:4､7:3) were studied in this paper. The result showed that the height and yield of both alfalfa and smooth bromegrass in the7:3 trail were remarkably improved. The total annual forage production of different proportion mixture sward for both control and trial has significant difference (P<0.01). The fertilization made the stem/leaves for both alfalfa and smooth bromegrass in the 7:3 trail lower than control‚but it had little effects on alfalfa/smooth bromegrass in the 5:5 and 6:4 trail. The yield coefficient of variation in7:3trail was the least.The fertilization made the 7:3 trail mixture sward have higher growth performance‚quality and yield.