Polyethylene　glycol　grafted　calcium　alginate　hydrogel　microspheres　are　synthesized　by　ring-opening　and　addition　reaction　of　epoxy　chloropropane.　FTIR,　C-13　NMR,　optical　microscope,　SEM,　TG,　and　DSC　are　used　for　characterization.　Swelling　behaviors　are　studied　and　it　is　found　that　polyethylene　glycol　grafted　calcium　alginate　microspheres　are　improved　in　anti-swelling　properties.　Protein-imprinted　polyethylene　glycol　grafted　calcium　alginate　hydrogel　microspheres　exhibit　enhanced　specific　rebinding　quantity　(11.16　mg/g)　and　selective　recognition　properties　(4.71　against　BHb),　towards　target　molecule　in　the　presence　of　competing　protein,　compared　with　that　of　the　unmodified　samples　(4.96　mg/g　and　1.75,　respectively).　(c)　2016　Wiley　Periodicals,　Inc.