本试验采用正交旋转回归设计的方法，选取氮（ｘ１）、磷（ｘ２）、有机肥（ｘ３）三个因素为决策变量，以马铃薯鲜薯产量为目标函数，通过田间试验获得的数据，建立了冀西北旱地马铃薯产量与参试因子间的数学模型。对模型进行解析的结果表明：施用有机肥对旱地马铃薯增产很重要，但施氮磷化肥也能增产；而且有机肥施用可以促进氮肥的增产效果，降低磷肥的增产效果。最后，通过计算机模拟寻优获得了１５００ｋｇ／６６７ｍ２以上施肥方案。 In this study, orthogonal rotation regression method was used to select three factors of nitrogen (x1), phosphorus (x2) and organic fertilizer (x3) as decision variables. The yield of potato was taken as objective function, A mathematic model was established between the yield of potato and the participating factors in dry land in northwestern Hebei. The results of the model analysis showed that the application of organic manure was very important for the increase of potato yield in dry land, but the application of nitrogen and phosphorus fertilizers also increased production. Moreover, the application of organic manure could promote the yield increase of nitrogen fertilizer and reduce the yield increase of phosphate fertilizer. Finally, 1500kg / 667m2 fertilization plan was obtained by computer simulation.