Abstract: Cr(VI) is a highly toxic heavy metal. Reducing Cr(VI) to Cr(III) by microorganism is an effective way to solve Cr(VI) pollution. Enterobacter sp. L6 was a dissimilatory iron-reducing bacterium isolated from marine sediments, A₆₀₀ is (0.25±0.03) when inoculated, after fermentation for 12 h, the cell density A₆₀₀ reached (1.04±0.05), the Fe(II) concentration of culture was (0.80±0.03) mmol/L. As the processing of fermentation, A₆₀₀ and the cumulative Fe(II) concentration began to decrease. After 36 hours, the cell density A₆₀₀ was (0.81±0.04) and Fe(II) concentration was (0.63±0.01) mmol/L respectively. In the process of anaerobic fermentation, there was a significant coupling relationship between cell growth and dissimilatory reduction of Fe(III). The results of Cr(VI) reduction by the dissimilatory iron-reducing bacterium L6 showed that strain L6 could grow and reduce Cr(VI) within the Cr(VI) concentration of 0~24 mg/L. When Cr(VI) concentration was 4, 8 and 12 mg/L, the reduction rate of Cr(VI) could reach 100%. When Cr(VI) concentration was 16 mg/L, the Cr(VI) reduction rate was 2.11 times that of control no Fe(III) added. When Cr(VI) concentration was 20 mg/L or 24 mg/L, Cr(VI) could still be reduced. The results showed that the iron-reducing bacteria using Fe(III) as electron acceptor could significantly improve the reduction rate of Cr(VI), which provides experimental data support for microbial remediation of Cr(VI) pollution.