The optimization compound design (311-A) was used to conduct field experiment to study the effects of the different ration of nitrogen,phosphorus and potassium on yields of sugarcane.By using SAS system software analysis,the regression models of fertilizers application and quadratic of three factors were established,and the optimum allocation and range of N,P_2O_5,K_2O on yield and sugar yield of sugarcane were obtained.For the optimum range of N,P_2O_5,K_2O of yield scheme:N=268.61312.23 kg/hm~2,P_2O_5=130.66141.31 kg/hm~2,K_2O=322.41344.82 kg/hm~2,NP_2O_5K_2O=10.450.491.101.20,predicted value at the maximum yield is 112.672 kg/hm~2;For the optimum range of N,P_2O_5,K_2O of sugar yield scheme:N=257.91290.83 kg/hm~2,P_2O_5= 139.03158.05 kg/hm~2,K_2O=325.28350.57 kg/hm~2,NP_2O_5K_2O=10.541.201.26,predicted value at the maximum sugar yield is 16.311 kg/hm~2.For the optimum allocation of N,P_2O_5,K_2O of yield scheme:N=311.72 kg/hm~2,P_2O_5=140.80 kg/hm~2,K_2O=344.41 kg/hm~2,NP_2O_5K_2O=10.451.10;For the optimum allocation of N,P_2O_5,K_2O of sugar yield scheme:N=290.60 kg/hm~2,P_2O_5=157.80 kg/hm~2,K_2O=350.38 kg/hm~2,NP_2O_5K_2O=10.541.21.