Abstract: A 3-year experiment was conducted under greenhouse conditions with different cultivation patterns (organic, integrated and conventional cultivation) to investigate the kind and epidemic characteristics of tomato main diseases. The results show that the main diseases of tomato under greenhouse are downy mildew, tomato leaf muld, early and late blight. Soil-borne and physiological diseases tend to increase due to low temperatures and high humidity in greenhouses. The incidence of downy mildew increases from year to year. Tomato main diseases under organic cultivation are less severe than those under other patterns in the same year. Control effect of early blight under organic cultivation respectively increases by 22.2%~57.1% and 36.4%~66.7% compared with integrated and conventional cultivation patterns. Those for downy mildew and late blight under organic cultivation respectively increase by 16.4%~54.9% and 37.7%~73.9%, 26.3%~44.3% and 47.5%~55.4% over integrated and conventional cultivation patterns.