Abstract: Three factors design with universal quadratic rotation combination was used to established the effect models of the application rates of N, P and K fertilizer and the bulbous growth quantity of the plant of Lycoris radiata. The testing results showed that the quadratic regression model gave better simulation. According to the analysis of the main effect of fertilizer, it showed that N, P and K had different influences on the bulbous growth quantity, the influences on L.radiata were in such decrease order as K, N, P. Twofactor interaction analysis showed that there was a positive interaction between N and K, N and P, P and K. Computer simulation showed that the optimum fertilization combination for L.radiata was that N, P, K fertilizer amount were 422.4—702.2 kg/hm2, 363.6—573.4 kg/hm2, 299.9 kg/hm2, respectively. Key words: Lycoris radiata; fert