Abstract Adult male urine contains glycoprotein fractions which do not pass Visking dialysis bags under normal pressure but are ultrafilterable when the bags are subjected to a negative pressure of about 700 mm Hg. These fractions represent about 75% of the total nondialyzable carbohydrate of male urine. Fractionation of ultrafiltrates by isopropanol and ether, followed by repeated continuous flow electrophoresis on glass fiber sheets, yielded about 40 glycoprotein fractions which differed from each other in the ratio of sialic acid to fucose and in electrophoretic mobility. The fractions obtained after repeated electrophoresis showed only one peak in free boundary electrophoresis at pH 8.6. Three different compositional patterns, characterized by different ratios of galactose to mannose, glucosamine to galactosamine, fucose to hexosamine, and sialic acid to fucose, were found among the fractions. Evidence is set forth that these patterns are related to different origins of these glycoproteins.