Abstract: Garlic seedling，no-heading Chinese cabbage or leaf lettuce was rotated with two season continuous cropping tomato during winter fallow season under plastic tunnel substrate cultivation. Microorganism groups，biomass and enzyme activity of the rotated substrate and yield and root vigor of afterculture tomato were measured to test the effect of rotating different vegetables on preventing of the continuous cropping obstacle of tomato. It showed that rotating with garlic seedling，no-heading Chinese cabbage and leaf lettuce significantly increased the number of total micro-biomass，bacteria number and ratio of bacteria to fungus in substrate. However the number of fungus decreased. Besides，relatively higher level of sucrase，urease，alkaline phosphatase and catalase activity in the substrate was recorded in all the rotating treatments. Among the three vegetables，garlic seedling showed the best rotating effect on microorganism group and enzyme activity of substrate and yield and root vigor of the after culture tomato during the whole growth season. In conclusion，rotating vegetables in substrate can improve the microorganism environment，increase the enzyme activity，and prevent the obstacle of continuous cropping of tomato and increase the harvest of rotating vegetables.

Key words: tomato, rotation, organic substrate, continuous cropping, microorganism amount, enzyme activity