Abstract: To determine the optimum fertilization for rice cultivar Gengxian No.1, field plot experiment using orthogonal rotational combination design with three factors and five levels was conducted to investigate the effects of fertilizers with different ratios of N, P and K on the yield component of Gengxian No.1. The results showed that the optimum fertilization model include 46% urea, 255 kg/ hm2; 17% calcium superphosphate, 600 kg/ hm2 and 50% potassium sulfate, 150 kg/ hm2, under which the yield could exceed 8 829 kg/ hm2. The optimized mathematical models was created between the maximum tillering, formation of spike from the tillers, yield and the fertilizer, which reached significant level.