Abstract: To obtain optimal cultivation conditions for tomato in greenhouse, an experiment was conducted to explore the effects of different planting densities, potassium levels and nitrogen levels on tomato yield. The response surface methodology was applied to optimize the main cultivation factors including planting density, nitrogen level and potassium level, and a quadratic regression equation was established. The results show that the planting density, potassium level and nitrogen level have noticeably significant effects on tomato yield (p0.01), and the order of the significance is: planting density potassium level nitrogen level. There are obvious interactions between the planting density and nitrogen level, and the planting density and potassium level (p0.01). However, the interaction between the nitrogen level and potassium level is not significant (p0.05). The multivariate quadratic regression model of the yield of tomato and the planting density, nitrogen level and potassium level is highly significant (p0.01). The optimal cultivation conditions are that the planting density is 48300 plants/ha, the nitrogen level is 262 kg/ha, and the potassium level is 513 kg/ha. Under these conditions, the yield of tomato in greenhouse is 119381 kg/ha, while the yield from verification