Abstract: The effect of redox potential regulation on the metabolites distribution in succinic acid production by anaerobic fermentation of Actinobacillus succinogenes was studied. In the serum bottle fermentation，potassium ferricyanide and dithiothreitol which did not have inhibition on fermentation，were selected as the oxidizing agent and reducing agent respectively. Potassium ferricyanide and dithiothreitol were used to control redox potential from －100 mV to －450 mV in 3 L fermenter. It was shown that the optimum redox potential or oxidoreduction potential (ORP) for cell growth and succinic acid production was －350 mV. Comparing with the fermentation without redox potential regulation，the productivity of succinic acid and the ratio of succinic acid to acetic acid enhanced from 0.75 g/(L·h) to 1.18 g/(L·h) and 2.5 to 3.9 respectively.