Abstract: The objective is to provide evidence for the high-quality and high-yield cultivation of oats in semiarid farm and pastoral areas of northwest China. 23 treatment plots of random arrangement were designed according to the four factors quadratic regression orthogonal rotary (? implementation) to study the seeding time, seeding rate, effects of nitrogen and phosphorus on yield and quality of naked oats‘Dingyou No.9’. The results showed that the seeding time and nitrogen rate had synergistic action on oats yield. The same condition appeared between seeding time and phosphorus rate. Increasing nitrogen and phosphor could raise oats crude protein and β- glucan, but excessive application of fertilizer could reduce the yield. The effect order of the four cultivation factors on yield and quality was nitrogen rate＞ phosphorus rate＞seeding time＞ seeding rate successively. The best synergistic cultivation mode of the four factors for‘Dingyou No.9’is: seeding time in late April, nitrogen rate of about 106-147 kg/hm2, planting density of 120 kg/hm2, and phosphorus rate of 300-330 kg/hm2.