| Using orthogonal design, the study aims to investigate the effects of irrigation and fertilization on yield and quality of tomato under drip irrigation. The optimal practices of irrigation and fertilization were proposed according to the established model of regression relationship between water and fertilizer amounts and yield as well as score of quality. The quality was graded with analytic hierarchy process (AHP). The result showed that the established model fitted well and can be used to analyze the effects of irrigation and fertilization on yield and quality. Impact of water on the yield and quality was different from that of fertilizer. In the yield model, coefficient of irrigation (0.78, X1), was greater than that of fertilization (0.35, X2), showing a larger influence of water on yield than that of fertilizer. In the quality model, coefficient of fertilization (0.22, X2) was greater than that of irrigation (0.14, X1), indicating a larger influence of fertilizer on quality than that of water. The yield and quality of tomato declined in low or high level of water and fertilizer, so the amount of irrigation water and fertilizer must be managed reasonably. Taking yield and quality into consideration, the optimum amount of irrigation water was 2 803.36～3 420.93 m3·hm-2, and fertilizer amount was 286.01～334.78 kg·hm-2, P2O5 143.00～167.39 kg·hm-2, and K2O 286.01～334.78 kg·hm-2. |