A series of vinyl acetate (VAc)-divinylbenzene (DVB) copolymeric microspheres were prepared by suspension copolymerization. The surface hydroxyl group onto the VAc-DVA copolymeric microspheres can be obtained by saponifiction reaction on their surface. By reaction between the reactive chorine group of a dye and the hydroxyl groups on the VAc-DVB copolymeric microspheres, cibacron blue F3G-A, as an affinity ligand, was covalently immobilized on the surface of the VAc-DVB copolymeric microspheres. The characterization of surface functionalizationed VAc-DVB copolymeric microspheres was studied by means of FTIR and diffuse reflectance FTIR spectroscopy. The results indicate that DR-FTIR spectra give out more detailed information of the modified microspheres' surface than FTIR spectra does.