Glycopeptides were prepared by pronase digestion of the urea extract of dermis of two isogenic mouse strains C3H/He and C57BL/6. 2) The major glycopeptide fractions from both strains contain, glucosamine, galactose, mannose, fucose and sialic acid. 3) The sugar composition, the behaviour on gel filtration and yields of the glycopeptides with identical electrophoretic mobilities, isolated from the two strains, were identical.