The consequences of extensive uses of fossil fuels have raised two severe problems including the issues of depletion of energy resources in the near future and global climate change. Considering the energy security and the global environment, there is an urgent need in developing a clean and renewable energy source. In Taiwan, cellulose-containing agriculture wastes such as rice straw were considered as potential materials for bioethanol production. Currently, 20 to 25% unconverted organic wastes are expected from cellulose-to-ethanol production processes and these wastes will cause serious environmental concerns and problems when cellulose-to-ethanol production goes to an industrial-scale mass production. This study investigated biological hydrogen production potential of organic residues generated during ethanol production processes using rice straw as substrate. In this study, cellulose-degrading and hydrogen-producing bacteria were successfully enriched in a fed-batch reactor using α-cellulose as substrate. Based on cloning and sequencing results, Clostridium cellulose-like, reported as thermophilic cellulose-degrading bacteria, and Clostridium thermopalmarium-like, report as hydrogen-producing bacteria were dominant microorganisms in the enriched culture. The enriched culture was used in a series of biological hydrogen production potential tests for organic residues generated during ethanol production processes using rice straw. The results indicated that a maximum hydrogen production rate of 7.6 mL-H2/hr and a hydrogen yield of 3.4 mmole H2/g COD can be attained. The results suggest that organic residues generated during ethanol production processes using rice straw can be feasible for additional energy recovery.