Petroleum hydrocarbon and chlorinated hydrocarbon multi-plumes usually coexist under nature conditions. The disposal of the contaminated plume is focused on the utilization of the products from granular iron permeable reactive barriers (PRBs) which can remove chlorinated hydrocarbons as the electron acceptor to biodegrade BTEX in the aquifer. Benzene and toluene are the most toxic compounds and tend to exist for a long time in the aquifer. This study focused on the biodegradation of benzene and toluene by using Fe(Ⅲ) from the Fe(OH)3-coated sand under anoxic conditions. Data obtained show that the biodegradation of benzene and toluene occurs when Fe(Ⅲ) is used as the only electron acceptor. After incubating, the rate of biodegradation will obviously increase. The biodegradation experiment indicates that the biodegradation rate of toluene is faster than that of benzene. The half life of benzene and toluene are 4.02 and 3.81 days respectively.