Abstract: A pot experiment was conducted with a soil originally contaminated with different concentrations of lead and cadmium, to determine the accumulation characteristics of lead and cadmium in 8 kinds of vegetable species and their effects on the growth of vegetables. The purposes of this study were to discover the relationship of lead and cadmium concentrations in vegetables and soil and to find the safety thresholds of lead and cadmium concentrations in soil for the eight vegetables. The results indicated that the cabbage and baby bokchoi grew well and their growth weren’t inhibited, while the growth of other species was inhibited to varying degrees with the increase of lead and cadmium concentration. The degree of growth inhibition of vegetables was in the descending order of celery, lettuce, daucus carrot, cowpea, pepper, tomato, cabbage and baby bokchoi, which was in accordance with their capacity of lead and cadmium accumulation. There were significant linear correlations between lead, cadmium concentrations of celery and soil (R²=0.923, 0.956). The critical values of lead in soil for different vegetables were in order of: leaf vegetables (cabbage, baby bokchoi) > root vegetables (lettuce, carrot) > beans (cowpea) > celery and pepper. The critical value of lead in soil wasn’t fixed for tomato. The critical values of cadmium in soil were the same for the 8 vegetables.

Key words: organic acid., open top chamber, elevated ozone concentration, rhizospheric soil, enzyme activity