An epoxy-group-containing vinyl monomer, i.e., glycidyl methacrylate, was graft-polymerized onto polyethylene particles with an average diameter of 35 mu m at various reaction temperatures within 278-333 K. The produced epoxy group was converted into a diethylamino group as an anion-exchange group. From the equilibrium binding capacity of the resultant particle-packed bed for bovine serum albumin (BSA) and the pressure loss required for a protein solution to flow through the bed, the formation of graft chains that were sufficiently long to hold BSA in multilayers and allow convective flow among them was predicted. The achieved ideal adsorption characteristics enabled a higher flow rate of the protein solution, which leads to a higher overall adsorption rate of the protein because of convective flow among the graft chains.