Abstract: Some anaerobic fermentation bacteria wtih simultaneous dissimilatory iron reduction and hydrogen production have been paid more and more attention for dual characteristics of energy-saving and environment-friendliness. A Fe(Ⅲ)-reducing bacterium, Enterococcus sp. ZQ21 isolated from marine sediment was used to analyze the characteristics of microbial Fe(Ⅲ) reduction coupled to hydrogen production. Strain ZQ21 could reduce Fe(Ⅲ) with iron reductase activity of 3.66U when iron hydroxide was as electron acceptor. While, using ferric citrate, strain ZQ21 had the higher iron reductase activity of 4.40U. In addition, strain ZQ21 was capable of hydrogen production under the culture condition of Fe (Ⅲ) reduction. Hydrogen production of strain ZQ21 was (1395.30 ± 4.79) mL/L, which significantly increased hydrogen production compared the control (23.20 ± 2.09) mL/L. According to the gas chromatography analysis, for strain ZQ21, ethanol and butyric acid became the major soluble production when electron acceptors were ferric citrate and iron hydroxide respectively. This result indicates that strain ZQ21 has the ability of high microbial Fe (Ⅲ) reduction and hydrogen production, which will provide evidence for the application of dissimilatory Fe(Ⅲ)-reducing bacteria for the characteristics of energy-saving.