With the aim to exploring optimum fertilizer dosage of nitrogen（N）,phosphorus（P₂O₅） and potassium（K₂O）of winter wheat new cultivar Xin Dong 42 in Ili River Valley winter wheat cultivation area,the "3414" fertilizer experiment was carried to analyze the effects of nitrogen（N）,phosphorus（P₂O₅） and potassium（K₂O） combined application dosage on grain yields and economic benefits of Xin Dong 42.The results showed that:compared with the control,the yields and economic benefits Xin Dong 42 were improved by each formula fertilization treatment.With the increase of nitrogen,phosphorus,and potassium fertilization levels,the variation trend of grain yields and economic benefits were increased firstly and decreased latterly.Among the 14 treatments,N₂P₂K₂ treatment（N 165.60 kg/ha,P₂O₅110.40 kg/ha,K₂O 45.90 kg/ha） had the highest yield and economic benefits,which was 8 036.03 kg/ha and 18 044.85 yuan/ha respectively.The optimal analysis of the model showed that it was reasonable and feasible to make the fertilization decision by using the ternary fertilizer efficiency function model.The recommended amount of fertilizer was obtained by fitting the regression function model.When the maximum yield（8 081.05 kg/ha） was reached,the fertilization amounts of nitrogen（N）,phosphorus（P₂O₅） and potassium（K₂O） were 190.04,122.23 and 53.10 kg/ha,respectively.Nitrogen（N）,phosphorus（P₂O₅） and potassium（K₂O） fertilization amounts were 171.03,108.18 and 44.77 kg/ha,respectively when the best economic benefit（18 056.37 yuan/ha） was achieved.These results will provide guidance for the rational fertilization of winter wheat in Ili River Valley and provide basis for the establishment of fertilization index system in the future.