Abstract: Enterobacter aerogenes was irradiated by He-Ne laser to optimize the laser mutagenesis condition，and to test the heredity，aciduric and hydrogen-producing potential of the mutant. An aciduric mutant with steady hydrogen-producing capability，which was able to grow at acidic pH of 3.0，was obtained. Its capability of hydrogen production was measured in the batch culture experiment. The maximum hydrogen yield and hydrogen production rate was 1781 mL/L and 240 mL/(L•h)，which were 48% and 32% higher than those of the parent strain，respectively. The results demonstrated that He-Ne laser mutagenesis could be used in the field of hydrogen-producing microorganism．