Abstract: The effect functions of N.P.K coordinative application on economical yield,fertilization profit and N ratio of split application at different growing stage of scallion were studied by the field experiments with 311-A best regression design of supposed saturation and 3,2 saturated design of single shape check.The results showed that the best N,P,K fertilization quantity for scallion with maximum economical yield was N 317.25 kg·hm-2,P2O56.26 kg·hm-2,K2O 93.34 kg·hm-2respectively.The best N.P.K fertilization quantity for scallion with best fertilization profit was N 310.76 kg·hm-2,P2O5 1.53 kg·hm-2 and K2O 89.93 kg·hm-2.The better N fertilization quantity at different growing stage of scallion (basal dressing,former and latter topdressing) was 74.08、112.24 and 124.68 kg·hm-2 respectively.At the equivalent fertilizer,the quality of scallion was affected by the N,P,K fertilization quantity and N fertilization periods.