The epidermal organ of the leech contains a complex glycoprotein molecule of mucus, The mucus excreted from annelids plays significant role in protection against desiccation and parasites. Mucus: from the Korean native leech, H. nipponia, was investigated for biochemical characteristics for possible development oi bismaterials of cosmetic and pharmaceutical agents. The leech skin mucus was heavily glycosylated mucin-like protein with a high molecular weight comprised 80% carbohydrate and 20% protein, Threonine, serine, and glycine were the major components of the isolated protein and these accounted for 50% of total amino acids. The carbohydrate portion contained glucosamine. galactosamine, galactose, glucose, mannose and sialic acid in oligosaccharide form linked with threonine and serine residues of the glycoprotein.