Anaerobic hydrogen fermentation converting organic wastes to clean hydrogen energy is a renewable technology for hydrogen production. This study developed a technology to immobilize hydrogen producing bacteria on granular activated carbon. It was investigated that the effects of organic loading impact on immobilized hydrogen production system. It was found that hydrogen production yield increased from 2.85 L to 5.2 L as COD increased from 2000 mg/L to 6000 mg/L. The liquid fermentation products were ethanol and acetic acid with percentage of 48.97% and 40.26%, respectively. VSS increased from 4555 to 5450 mg/L which results in the increasing of hydrogen yield. Therefore, immobilized anaerobic sludge by grunular activated carbon could be a promising immobilization technology for biohydrogen fermentation.