Polysaccharide is the major composition of the wastewater discharged from the paper mill and the starch processing plant. Biofuel recovery of carbohydrate-containing wastewater is feasible with both anaerobic hydrogen fermentation and methane fermentation. In this study, the bio-hydrogen production process was promoted with two strategies: (1) Selective cellulose-hydrolying and hydrogen-producing bacteria were screened and enriched with heating pretreatment and high substrate loading for the predominant Clostridium species. Anaerobic granular sludge was inoculated from an UASB in a paper wastewater treatment plant, after heating pretreatment, the endosporous Clostridium microbes were enhanced for high hydrogen production. And it would be monitored with scanning electron microscopy and molecular biological technology for microbial morphology and 16S rDNA identification. Biodegradation study was conducted with measurement of α-amylase activity of the existed anaerobes degrading starch. This enzymatic indicator could be provided to evaluate the biodegradability of polysaccharides. On the other hand, (2) the Biochemical Hydrogen Potential tests (BHP tests) were conducted to investigate the biohydrogenation potential of the acclimated anaerobes degrading the paper mill wastewater and other high cellulosic substrates. The soluble carbohydrate converted in BHP tests was to be the critical indicator substrate for the hydrolytic characteristic of cellulosic substrates.