Abstract: The different 0₃ concentration experiments on spinach and Chinese cabbage were conducted in open top chamhers and the impacts of different 0₃ concentration on the growth and development，physiological characteristic parameters of spinach and Chinese cabbage were analyzed．The results show that the stomatal resistance is increased，photosynthesis rate and the biomass of above-ground and sub-ground are decreased in large scale when the o₃ concentration enrichment．When O₃ concentration arrives at 200umol／kmol，the above ground biomass of spinach and Chinese cabbage are less than 1／9 and 1／3 and the sub-ground biomass are decreased by 79．8％ and 69．3％．respectively．