The　graphene　oxide　nanoribbons(GONRs)　were　prepared　by　longitudinallu　unzipping　multiwalled　carbon　nanotubes,　and　then　were　modified　with　isophorone　diisocyanate(IPDI).　The　functionalized　graphene　oxide　nanoribbons(IP-GONRs)/thermoplastic　polyurethane(TPU)　composite　films　were　prepared　by　solution　on　the　coating　machine.　The　effects　of　IP-GONRs　on　barrier　and　mechanical　properties　of　TPU　films　were　studied.　The　SEM　and　XRD　results　show　that　IP-GONRs　in　TPU　matrix　are　fully　exfoliated,　uniformly　dispersed　and　substantially　paralleled　along　surface　of　nanocomposite　films.　The　oxygen　transmission　rate　of　TPU　film　declines　by　about　67%　at　low　IP-GONRs　loading　of　3.0%.　A　remarkable　improvement　on　barrier　properties　of　IP-GONRs/TPU　nanocomposite　films　is　achieved.　This　is　attributed　to　excellent　impermeable　property　of　IP-GONRs,　their　full　exfoliation,　and　parallel　in　the　TPU　matrix　and　the　strong　interfacial　adhesion　between　IP-GONRs　and　TPU　matrix.　The　improved　properties　of　the　composite　film　could　lead　to　potential　applications　in　food　packaging　and　lightweight　mobile　gas　storage　containers.　©　2016,　Editorial　Board　of　Polymer　Materials　Science　&　Engineering.　All　right　reserved.