Hydrogen was produced from various marine macro-algae (seaweeds) through anaerobic fermentation using an undefined bacterial consortium. In this study, anaerobic fermentation from various marine macro-algae for Ulva lactuca, Porphyra tenera, Undaria pinnatifida, and Laminaria japonica was studied. From this analysis Laminaria japonica was determined to be the optimum substrate for hydrogen production. When L. japonica was used as the carbon source for enhanced hydrogen production, the optimum fermentation temperature, substrate concentration, initial pH, and pretreatment condition were determined to be $35^{circ}C$, 5%, 7.5, and BT120 (Ball mill and thermal treatments at $120^{circ}C$ for 30 min), respectively. In addition, hydrogen production was improved when the sludge was heat-treated at $65^{circ}C$ for 20 min. Under these conditions, about 4,164 mL of hydrogen was produced from 50 g/L of dry algae (L. japonica) for 50 h, with a hydrogen concentration around 34.4%. And the maximum hydrogen production rate and yield were found to be $70;mL/L{cdot}h$ and 28 mL/g dry algae, respectively.