Polyacrylonitrile　(PAN)　membrane　has　been　widely　used　in　traditional　ultrafiltration　processes.　However,　the　nonspecific　adsorption　of　proteins　on　PAN　membrane　reduces　the　flux　and　increases　the　operation　cost　by　requiring　extra　process　of　cleaning.　Generally,　hydrophilic　and　electrically　neutral　reagents　such　as　polyzwitterionic　materials　were　used　to　improve　its　anti-fouling　performance.　In　the　present　study,　a　negatively　charged　oligodeoxynucleotide　with　a　hairpin　structure　was　first　grafted　onto　PAN　membrane　to　improve　its　anti-fouling　capacity.　The　oligodeoxynucleotide　modified　(OPAN)　membranes　were　characterized　in　terms　of　chemical　composition,　morphology,　and　surface　properties　indicating　that　the　oligodeoxynucleotide　could　successfully　be　bonded　onto　the　PAN　membrane.　The　anti-protein-fouling　properties　of　the　membrane　were　tested　using　static　protein　adsorption　and　dynamic-filtration　experiments.　The　experimental　results　indicate　that　the　flux　ecovery　rate　of　the　OPAN　membrane　was　much　higher　than　that　of　the　pure　PAN　membrane.　The　improved　anti-fouling　performance　of　the　membrane　is　suggested　to　be　attributed　to　the　steric　hindrance　and　electrostatic　repulsion　between　the　oligodeoxynucleotides　and　the　proteins.　©　2014　Elsevier　B.V.