The invention is a glycolipid useful in treating autoimmune diseases and a medicine thereof as active ingredient for autoimmune diseases, represented by the formulawherein R1 is an aldopyranose group, R2 is a hydrogen atom or a hydroxyl group, R3 is —CH2—, —CH(OH)—CH2— or —CH═CH—, R4 is a hydrogen atom or CH3, x is 0-35, y and z represent integers satisfying y+z=0-3.
