Abstract: Study on different density and fertilizer application of N,P,K on Helianthus tuberosus. The results show that, the order of the factors which can influence the yield of Helianthus tuberosus is density〉K2O〉N〉 P205. The level result shows that, the combinations of the highest yield are： A1B2C2D2： the density of Helianthus tuberosus is 70cm~50cm, fertilizing amount of N is 3.50kg/666.7m2, fertilizing amount of P is 6.90kg/m2,fertilizing amount of P2O5 is 5.0kg/666.7m2. The experiment provides the scientific basis for collecting the combinations.