A glycolipid was isolated and purified from goat erythrocytes, by repeated chloroform methanol extraction, followed by silicic acid column chromatography. The glycolipid, on acid hydrolysis, showed the presence of glucosamine, galactose, glucose and ceramide. The glycolipid is immunologically active in inhibiting hemolysis of goat erythrocytes sensitized with their antibodies in the presence of complement and also in inhibiting the agglutination of B group erythrocytes and anti B serum. The first terminal group of the glycolipid is found to be β D galactose by enzymatic hydrolysis with β D galactosidase. The second terminal group is β N acetyl D glucosamine. The remaining part of the glycolipid was identified to be D galactose (β 1→4) D glucose (β 1→1) ceramide, by comparison of its R(f) value with that of cytolipin H. Further enzymatic hydrolysis of the remaining part with rat brain enzymes in two stages confirmed its cytolipin H structure. Thus, the structure of the glycolipid from goat erythrocytes is D galactose (β 1→4/3) N acetyl D glucosamine (β 1→3) D galactose (β 1→4) D glucose (β 1→1) ceramide.