In this study, we investigated the effect of reaction factors on enzymatic hydrolysis of Hizikia fusiforme, which is brown algae in marine biomass resource, using commercial enzymes. The composition of H. fusiforme is 38.9% of reducing sugar, 4.8% of moisture, 17.8% of ash, and 38.5% of others. In the condition of 1-5% substrate, the increase of substrate concentration enhanced the increase of reducing sugar formation; however, the hydrolysis yield did not increase after 24 h. After reaction of 75 h, conversion yield of reducing sugar were obtained to 16.45%, 17.99%, and 14.55% at 1, 2.5, and 5% substrate, respectively. As a result of effect of enzyme amount, the formation of reducing sugar did not show considerable change at 1% substrate. However, in the condition of 2.5% substrate, the great change of reducing sugar formation was observed by the increase of enzyme amount. The conversion yields of reducing sugar were obtained to 18.77% and 22.83% at 1% and 2.5% substrate with 30% enzyme, respectively. As a result of heat treatment of biomass, the high yield was obtained in 2.5% substrate and the yields were increased to 0.06-7.2% by the heat treatment. This result will provide the basic information for production process of biofuels and chemicals from marine biomass H. fusiforme.