Submerged cultivation of Hericium erinaceus in various media was studied. The yield of the biomass was shown to depend mainly on the carbon source, whereas the content of water soluble polysaccharides depended mainly on the nitrogen source. The optimal medium composition provided the biomass yield of 21-23 g/l in 7 days. The biomass was characterized by the content of total protein, lipids and carbohydrates. In addition, the amino acid composition of the biomass was determined and shown to meet all the requirements of FAO/WHO concerning the amounts of essential amino acids (with exception of tryptophane). Oleinic and linoleic acids were identified as the main components of the fatty acids. Two water soluble polysaccharide fractions differing in solubility in aqueous ethanol were isolated and shown to contain rhamnose, fucose, xylose, glucose and galactose in different proportions. Vitamins B1, B2, B6, PP and E, ergosterol and coenzyme Q were also detected in the biomass of H. erinaceus.