Polyurethane　grafted　calcium　alginate　hydrogel　microspheres　intended　for　bovine　serum　albumin　imprinting　were　prepared　and　characterized.　The　grafting　modification　was　performed　prior　to　the　assembling　of　protein　template　with　hydrogel,　which　was　advantageous　to　maintain　protein　conformation　and　construct　more　accessible　imprinted　sites.　It　was　found　that　the　imprinted　hydrogel　had　higher　affinity　to　template　molecules　after　modification.　Investigations　of　grafting　ratio　influence　on　specific　rebinding　and　competitive　properties　indicated　that　grafted　side　chains　were　beneficial　to　the　selective　recognition　of　protein.　(C)　2014　Elsevier　B.V.　All　rights　reserved.