NOVELTY - Pretreating lignocellulose biologically by (a) inoculating white rot fungi in lignocellulosic liquid culture medium, culturing, washing medium, drying the medium, (b) adding hydrogen producing bacterial solution (3 l) and Trichoderma viride crude enzyme mixture (7 l), adding pretreated cellulose to the liquid medium, passing nitrogen, and inoculating hydrogen producing bacteria seed liquid, and (c) subjecting the medium to anaerobic fermentation and stirring for simultaneously performing saccharification and fermentation.    USE - The method is useful for pretreating lignocellulose biologically and for producing hydrogen.    ADVANTAGE - The method reduces energy consumption for lignocellulose pretreatment and is environmentally-friendly and is efficient than the existing fermentation methodologies as fermentation inhibitors does not produces during the process. The method enables lignin treatment at a rate of 55.7% and the hydrogen production of 72.6 ml/g.    DETAILED DESCRIPTION - Method for pretreating lignocellulose biologically and producing hydrogen simultaneously, involves (a) inoculating white rot fungi in lignocellulosic liquid culture medium, culturing for 10-20 days at 29 degrees C under aerobic conditions, washing medium with water and drying by placing the medium in oven at 105 degrees C until constant weight of pretreated cellulose is obtained, (b) adding hydrogen producing bacterial solution (3 l) and Trichoderma viride crude enzyme mixture (7 l) to the medium, adding pretreated cellulose (150-350 g) to the above-cited liquid medium to obtain saccharifying and fermenting hydrogen producing culture medium, passing nitrogen having purity of 99.99% into culture medium, and inoculating seeds of liquid hydrogen producing bacteria, and (c) subjecting the inoculated medium to anaerobic fermentation for 24-72 hours under conditions having initial pH of 6.5 and temperature of 60 degrees C and stirring at 150 revolution/minutes (rpm) for simultaneously performing saccharification and fermentation, where the white rot fungi in step (a) is Phanerochaete chrysosporium (CGMCC 5.776). The lignocellulosic liquid culture medium (1 l) comprises (in g): ferrous sulfate (FeSO4) (0.008), yeast powder (7.5), potassium dihydrogen phosphate (KH2PO4) (3), calcium chloride (CaCl2) (0.034), glucose (20), lignocellulose (20), vitamin solution (1 ml) and distilled water (remainder). The lignocellulose is rice straw, wheat straw or maize straw powder. The vitamin solution comprises inositol (25), nicotinic acid (1), pantothenic acid (1), pyridoxine hydrochloride (1), thiamine hydrochloride (1), 4-aminobenzoic acid (0.2) and biotin (0.05) dissolved in 1000 ml of distilled water or lipoic acid (50 mg), biotin (20 mg), nicotine acid (0.35), thiamine hydrochloride (5 mg), paraaminobenzoic acid (50 mg), folic acid (20 mg), calcium pantothenate (50 mg), vitamin B12 (1 mg) and pyridoxine hydrochloride (100 mg). The hydrogen producing bacterial nutrient solution (1 l) comprises ammonium chloride (1), sodium chloride (1), dipotassium hydrogen phosphate (3), potassium dihydrogen phosphate (1.5), cysteine (0.5), magnesium chloride hexahydrate (MgCl2.6H2O) (0.5), potassium chloride (0.2), yeast powder (2), peptone (2), trace element liquid solution (1 ml), vitamin liquid (1 ml) and resazurin solution (0.1 weight/volume%). The trace element liquid solution (1 l) comprises ferrous chloride (1.5), zinc chloride (70 mg), boric acid (6 mg), manganese (II) chloride tetrahydrate (MnCl2.4H2O) (0.1), copper (II) chloride dihydrate (CuCl2.2H2O) (2 mg), cobalt (II) chloride hexahydrate (CoCl2.6H2O) (0.19), nickel (II) chloride hexahydrate (NiCl2.6H2O) (24 mg), sodium molybdate (Na2MO4.H2O) (36 mg), sodium tungstate (15 mg) and sodium selenate (VI) pentahydrate (Na2SeO4.5H2O) (15 mg). The T.viride crude enzyme in step (b) is cultured in liquid culture medium under aerobic conditions at 29 degrees C and stirred for 150 rpm for 4 days, subjecting the culture medium to centrifugation at 8000 rpm for 10 minutes, separating supernatant to obtain T.viride crude enzyme liquid. The size of the T.viride inoculum is 1x 1012-1x 1016 cells/l. The T.viride (CGMCC 3.2876) is from sugarcane scientific institute of Guangdong. The culture medium (1 l) for producing liquid enzyme comprises KH2PO4 (2), (NH4)2S04 (1.4), MgSO4.7H20 (0. 3), CaCl2 (0.3), bran (20), corn straw (10), bean cake powder (5), trace element liquid (1 ml) and distilled water (remainder), where the trace element liquid comprises ferrous sulfate heptahydrate (FeSO4.7H2O) (5), magnesium sulfate (MgSO4) (1.6), zinc sulfate heptahydrate (ZnSO4.7H2O) (1.4), CoCl2 (2), and distilled water (remainder). The seed liquid for the hydrogen producing bacteria is 4% liquid suspension containing bacteria in logarithmic phase.