Abstract: The developmental stages of greenhouse tomato were determined based on its biological characteristics, constancy of effective accumulated temperature and experiences of cultivation. They are sowing date, seedling stage, bloom and fruit setting stage, fruit developing stage, fruit gained first stage, fruit gained medium stage and fruit gained end stage, whose growing degree day values are 710.5, 110.5, 152.3, 302.9, 245.6, 2156.7, 200.5℃/d respectively. After these Ai parameters were determined, the development stage simulation model for long-term tomato growing in greenhouse was developed, which can systematically be used to estimate various developmental stages of long-term greenhouse tomato. The model was tested by using experiment data. The result showed that the simulated results agreed with the observed results well.