Abstract: n order to understand effects of different quantity of the potassium and phosphorus application and varieties on yield and main agronomic traits of straw-covering and no-tillage autumn potato in the ecological conditions of the Sichuan Basin, An orthogonal experiment with the mixed orthogonal table （L84×24） was carried out, the Mira and ChuanYu-No.5 were used as the planting materials. The results showed that the tuber yields have a significant difference among different treatment of the potassium and phosphorus application. It reached 0.01 significance level. The dry weight of Up-ground parts, height, diameter of stem and the dry weight of root did not show significant difference. But the tuber yield did not show significant difference among different treatment of varieties, and the dry weight of Up-ground parts, height, diameter of stem and the dry weight of root showed a significant difference among different treatment of varieties. It also reached 0.01 significance level. The experiment showed that when quantity of the potassium and phosphorus application were 315kg/hm2 and 270kg/hm2 , the yield of Mira could reach 24015kg/hm2 in the ecological conditions of the Sichuan Basin.