A field experiment was conducted to investigate the effect of different levels of nitrogen (N),phosphorus (P) and potassium (K) on growth characteristics and yield of yam.The results showed that the fresh weight and dry weight of the aboveground part increased and then decreased obviously during the growth period from sowing until harvest,and the highest value was observed at 120 d after sowing.The fastest rate of growth and dry matter accumulation of aboveground part both appeared at 90~120 d.While the fresh weight and dry weight of underground part gradually increased in the whole growth period,and the fastest rate of growth and dry matter accumulation also appeared in 90~120 d.The deficiency of N,P or K decreased the yam yield by 21.19%~41.17%,20.01%~26.07% and 4.97%~33.86%,respectively.In conclusion,the lack of N,P or K could affect the dry matter accumulation and growth of yam.Nitrogen is the major limited factor for yam growth,followed by K,and P is the least.Respectively,the yam yield showed two variation tendencies:parabolic or linear plus platform with the increasing of N,P and K application rate.According to the correlation equation of fertilization rate and yield,the optimum fertilization rate of yam is N 301.1 kg/hm2,P2O5 165.9 kg/hm2,and K2O 290.3 kg/hm2.