In　situ　grafting　on　surface　was　developed　to　modify　porous　microspheres.　Functional　monomers　were　grafted　onto　the　porous　microspheres.　The　grafting　yield　was　up　to　54.6%.　The　self-assembly　of　functional　monomer　and　L-tryptophan　molecules　was　verified　by　UV　spectrometry.　The　surface　imprinted　polymer　microspheres　(SMIPs)　were　synthesized　based　on　the　in　situ　grafting　on　surface.　The　competitive　binding　experiments　were　carried　out　to　assess　the　recognition.　The　results　showed　good　selectivity　of　the　SMIPs　towards　target　molecule.　Langmuir　and　Freundlich　adsorption　models　were　applied　to　description　of　the　experimental　adsorption　isotherm.　The　analysis　suggested　that　the　adsorbing　behavior　of　SMIPs　was　in　agreement　with　Langmuir　isotherm　equation.　©　(2011)　Trans　Tech　Publications,　Switzerland.