A polysaccharide-amino acid complex was prepared from ovalbumin by the use of a protease of Streplornyces griseus. The complex was found to be composed of aspartic acid, ammonia, N-acetylglucosamine and mannose, in the ratio of 1: 1: 3: 5. The reducing end of the polysaccharide was found to be glucosamine and C-1 of the glucosamine appeared to be involved in the linkage with the amino acid. By partial acid hydrolysis, compounds corresponding to asparaginylglucosamine could he isolated. Behaviours of the complex towards acid and alkali and the properties of the reduced complex were compared to those of an N-substituted glycosylamine of N-acetylglucosamine and its reduced form. Because of the contrary features between the complex and the glycosylamine, a linkage of iminoether (imidic acid ester or imido ester) type between aspartic acid and the polysaccharide was suggested.