The transport of selected polycyclic aromatic hydrocarbons（PAHs），phenanthrene (Phe)，anthracene (Ant) and pyrene (Pyr)，under conditions with and without bacteriostasis was studied through leaching experiments.The results showed that

microorganisms inhibited leaching of PAHs with a leaching rate of 8.74％，28.53％ and 13.56％ of Phe，Ant and Pyr respectively after 180 days’ leaching under the condition with bacteriostasis and 0.95％，1.47％ and 0.37％ after 240 days’ leaching under the condition without bacteriostasis. The tested 3 PAHs tended to be attached on the top of the soil under both conditions with and without bacteriostasis with 75% of Phe distributing at 0—2 cm from the feeding side，above 90％ of Ant distributing at 10 cm from the feeding side and 85％ of Pyr distributing at 4 cm from the feeding side after 240 days’ leaching.Microorganisms affected the PAHs transport by blocking and degrading.All of Phe，Ant and Pyr could be biodegraded.Before 60 d，PAHs were mainly degraded through the aerobic process while through the anaerobic process after 60 d.