A polymer brush containing a Diethylamino(DEA) group as an anion-exchange group was appended onto a polymer substrate by radiation-induced graft polymerization and subsequent chemical modifications. An anion-exchange group containing porous membrane in the form of a hollow fiber was prepared to immobilize Bovine serum albumin(BSA) as a chiral selector. Tryptophan(D-, L-Trp) solution was forced to permeate through the BSA multilayered porous membrane at a flow ranging from 10mL/h to 50 mL/h. D-Trp has a faster breakthrough behaviour than L-Trp due to the higher specificity of the BSA multilayered porous membrane to L-Trp. Diffusional mass-trasnfer resistance of L-Trp to BSA multilayered porous membrane was negligible because of the convective flow through the pores.