Poly(hydroxyethyl methacrylate–ethylen glycol dimethacrylate), p(HEMA–EGDMA), beads were prepared by suspension polymerization, and were decorated with fibrous poly(glycidyl methacrylate), p(GMA), via surface initiated-atom transfer radical polymerization (SI-ATRP). The functional epoxy groups of the beads were used for covalent immobilization of papain. The average amount of immobilized enzyme was 18.7mg/g beads. The immobilized enzyme was characterized by temperature, pH, operational and storage stability experiments. The maximum velocity of the free and immobilized enzymes (V max ) and Michaelis–Menten constant (K m ) values were determined as 10.7 and 8.3U/mg proteins and 274 and 465μM, respectively. The immobilized papain was operated in a batch reactor, and it was very effective for hydrolysis of different proteins (i.e., casein and cytochrom c).