Through potted plant experiments in the greenhouse, the influence of different concentrations of PAHs pollution on the stem height, basal stem diameter, growth rate and microbial number was measured. Results are as follows. PAHs have definite stimulating effects on the height growth of seedlings but inhibition on their ground diameter. With the increase of PAHs pollution concentration, the promoting effect on height growth decreases gradually and inhibition on ground diameter increases. After a decrease at the beginning, the microbial number measured in the po...