Commercial glucoamylase was immobilized on the polymer carrier produced by the binding of 4--8 mol.% 4,4'-diamine diphenyl oxide of the maleic anhydride copolymer with N-vinyl pyrrolidone. Two types of immobilized preparations were obtained: with covalent absorption and covalent attachment of the enzyme to the polymer. Glucoamylase activity of the first preparation was 20,000--60,000 and that of the second was 40--120 units/g polymer. Covalent-attached preparations showed a more prolonged action than covalent-absorbed ones.