Field experiments were conducted during 2008-2010 to investigate the effects of NPK fertilization on seed yield and economic benefit of a new hybrid cultivar of winter oilseed rape(Brassica napus L.)- Xiangzayou763,and to determine the optimum NPK ratio and dose in Hunan,China.The results showed that NPK ratio(1:0.50:0.50) with 180 kg/hm2 N,90 kg/hm~2 P_2O_5 and 90 kg/hm~2 K_2O was the optimum combination for the highest seed yield(2 231.13 kg/hm2) and economic benefit(9 816.97 Yuan/hm~2),of which 1 641.23 Yuan/hm~2 being set for fertilizer investment(VCR=4.11).Besides,the effects of N,P and K fertilizers on seed yield and oil production of winter oilseed rape were not identical.N had the greatest effect on plant growth of winter oilseed rape,followed by P and K.Total leaf number,green leaf number,leaf length and width,rhizome diameter,branch number,dry weight per plant and other agronomic characters in high N treatments were higher than those in low N treatments.By correlation and path analysis of yield components,the contribution rate to seed yield was found:effective silique number per plant>seed number per silique>1 000-seed weight. Field experiments were conducted during 2008-2010 to investigate the effects of NPK fertilization on seed yield and economic benefit of a new hybrid cultivar of winter oilseed rape (Brassica napus L.) - Xiangzayou763, and to determine the optimum NPK ratio and dose in Hunan , China.The results showed that NPK ratio (1: 0.50: 0.50) with 180 kg / hm2 N, 90 kg / hm ~ 2 P_2O_5 and 90 kg / hm ~ 2 K_2O was the optimum combination for the highest seed yield (2 231.13 kg / hm2) and economic benefit (9 816.97 Yuan / hm ~ 2), of which 1 641.23 Yuan / hm ~ 2 being set for fertilizer investment (VCR = 4.11) .Besides, the effects of N, P and K fertilizers on seed yield and oil production of winter oilseed rape were not identical. N had the greatest effect on plant growth of winter oilseed rape, followed by P and K.Total leaf number, green leaf number, leaf length and width, rhizome diameter, branch number, dry weight per plant and other agronomic characters in high N treatments were higher than those in low N treatments.By correlation and pat h analysis of yield components, the contribution rate to seed yield was found: effective silique number per plant> seed number per silique> 1 000-seed weight.