Abstract: 【Objective】 To clarify the effects of different nitrogen fertilizer treatments on growth, quality and yield of greenhouse tomatoes. 【Method】 The tomato variety Tianma 54 was used as the testing material and six nitrogen levels treatments were set: N0 (no nitrogen fertilizer), N1 (150 kg/hm²), N2(300 kg/hm²), N3(450 kg/hm²), N4(600 kg/hm²), and N5(750 kg/hm²). The purpose of this study was to find out the operating rule of nitrogen fertilizer in drip-tube tomato and the optimal amount of nitrogen fertilizer used in drip-tube tomato, and to provide theoretical basis for nitrogen management of drip-irrigation tomato.【Result】 The results showed that the accumulation of dry matter increased with the increase of nitrogen application in the two experimental years, and the maximum growth rate of dry matter appeared in 45.8-52.7 d. Leaf area index (LAI) varied significantly from 40 days to 80 days after planting, and reached its maximum at 60 days after planting, showing a parabolic trend of increasing first and then decreasing. Net photosynthetic rate (NPR) and SPAD value decreased with the increase of nitrogen application, while cell CO₂ concentration decreased with the increase of nitrogen application. The yield, nitrogen use efficiency and contribution rate of nitrogen fertilizer yield in N4 treatment were 9.35-10.26 t/667m², 42.61%-43.56%, and 33.89%-29.92%, respectively. 【Conclusion】 In this study, all the indexes considered, N4 (600 kg/hm²) treatment was the best one among the five nitrogen fertilizer treatments.