Abstract: With three factors design of universal quadratic rotation combination, the models were established on the effects of N, P and K fertilizer on growth of young plantation of Liriodendron chinese×L.tulipifera in the condition lacks P element. According to the test results, the quadratic regression model had better simulation effect of 1year plantation on height and volume, 2year plantation on diameter, while hardly effect on other growth targets. Through the analysis of the main effect of fertilizer, it showed that N, P and K had different influences on young plantation: P had the most dramatic influences, but N and K could also help promote the growth of young plantation. Twofactor interaction analysis showed that there was significant interaction between two fertilizer factors that could promote the plantations grow, among of which, N and P, P and K had more intensive interaction. By computer simulating, the optimum fertilization combination for growth of young plantation was urea 44—65 g per plant, superphosphate 188—261 g per plant and potassium chloride 26—44 g per plant, with the average increment of plant 1year height, volume and 2year diameter were (38.6±0.8) cm, (58.7±1.4) cm3 and (1.38±0.01) cm.