In this work, poly(HEMA-APH) nanoparticles were synthesized by surfactant-free emulsion polymerization technique. Magnetic behaviour was introduced by simple addition of Fe3O4 into the polymerization medium. Characterization of the nanoparticle was carried out by FTIR, ESR, SEM, AFM and EDX analyses. These synthesized magnetic nanoparticles were used for adsorption of lysozyme. For this purpose, adsorption conditions were optimized and maximum lysozyme binding capacity was found to be 278.8 mg g(-1) polymer in pH 7.0 phosphate buffer at 25(a similar to)C. Desorption and reusability properties of the nanoparticles were investigated and lysozyme adsorption efficiency did not change significantly at the end of the 10 successive reuses.