NOVELTY - Hydrogen is produced by inoculating Clostridium sp. strain H10 solution (8-12 vol.%) having cell concentration of 1x 1010 power/L to culture medium, culturing at 35 degrees C and pH of 7-8 in nitrogen (99.99 mass%) for 46-50 hours; and transferring the strain H10 to hydrogen-producing substrate (8-12 vol.%), fermenting by anaerobic fermentation at 34 degrees C, 90-110 rpm and pH 7-8 in nitrogen (99.99 mass%) for 22-26 hours.    USE - Method for producing hydrogen (claimed).    ADVANTAGE - The method shortens lag phase (i.e. by 20-30%), and has high utilization rate of cellulose (i.e. 65-75%) and high hydrogen producing rate (i.e. 1.8-2 mol hydrogen/mole hexose).    DETAILED DESCRIPTION - Production of hydrogen comprises inoculating Clostridium sp. strain H10 solution (8-12 vol.%) having cell concentration of 1x 1010 power/L to culture medium, culturing at 35 degrees C and pH of 7-8 in nitrogen (99.99 mass%) for 46-50 hours; and transferring the strain H10 to hydrogen-producing substrate (8-12 vol.%), fermenting by anaerobic fermentation at 34 degrees C, 90-110 rpm and pH 7-8 in nitrogen (99.99 mass%) for 22-26 hours. The culture medium (1 L) comprises dipotassium hydrogen phosphate trihydrate (2.9 g), potassium dihydrogen phosphate (1.4 g), ammonium sulfate (1.3 g), magnesium chloride hexahydrate (1 g), calcium chloride dehydrate (0.15 g), ferrous sulfate (1.25 mg), yeast powder (2 g), cellobiose (5 g), diazoresorcinal (2 mg), L-cysteine (1 g), ferrous chloride tetrahydrate (0.018 g), cobalt chloride hexahydrate (0.1 mg), cupric chloride dihydrate (0.1 mg), manganese chloride tetrahydrate (0.007 g), zinc chloride (0.001 g), boric acid (0.005 g), sodium selenate pentahydrate (0.1 mg), biomass (0.001 g), nicotinic acid (3.5 g), aneurine hydrochloride (0.003 g), p-aminobenzoic acid (0.002 g), calcium pantothenate (0.001 g), vitamin B12 (0.5 mg), pyridoxamine hydrochloride (0.001 g) and water (balance). The hydrogen producing substrate comprises dipotassium hydrogen phosphate trihydrate (2.9 g), potassium dihydrogen phosphate (1.5 g), ammonium sulfate (1.3 g), magnesium chloride hexahydrate (1 g), calcium chloride dehydrate (0.15 g), ferrous sulfate (1.25 mg), yeast powder (2 g), cellulose (7.5 g), diazoresorcinal (2 mg), L-cysteine (1 g), ferrous chloride tetrahydrate (0.018 g), cobalt chloride hexahydrate (0.1 mg), cupric chloride dihydrate (0.1 mg), manganese chloride tetrahydrate (0.007 g), zinc chloride (0.001 g), boric acid (0.005 g), sodium selenate pentahydrate (0.1 mg), biomass (0.001 g), nicotinic acid (3.5 mg), aneurine hydrochloride (0.003 g), p-aminobenzoic acid (0.002 g), calcium pantothenate (0.001 g), vitamin B12 (0.5 mg), pyridoxamine hydrochloride (0.001 g) and water (balance).