A pH-response polymer P-MMDN was synthesized and then ligand Cibacron Blue F3GA was immobilized on the polymer for affinity precipitation of cellulase. The isoelectric point of the affinity polymer was 5.0 and the recovery was 99.8% in presence of 0.8 mol/l Na2SO4. Optimal adsorptions could be achieved at pH 7.2 and 1.0 mol/l NaCl. FTIR confirmed that ligand Cibacron Blue F3GA was immobilized on the polymer and cellulase was adsorbed on P-MMDN-Cibacron Blue F3GA. The optimal eluant was 0.1 mol/l Tris-HCl (pH 7.1) with 20.0% glycol. The elution recovery of total cellulase activity and endo-glucanase activity was almost 84.4% and 99.8%, respectively. The SDS-PAGE showed the main bands with a molecular weight corresponding to that of the native cellulase. (C) 2012 Elsevier B.V. All rights reserved.