Gallium　nitride　nanowires　(GaN　NWs)　were　synthesized　by　plasma-enhanced　hot　filament　chemical　vapor　deposition　under　different　ratios　of　nitrogen　to　hydrogen,　which　the　GaN　powder　and　nitrogen　gas　were　used　as　the　Ga　and　N　sources.　The　characterization　results　indicate　that　the　GaN　NWs　are　grown　in　wurtzite　crystalline　structure　with　different　length,　diameters　and　surface　adsorption.　The　field　emission　of　GaN　NWs　was　measured　in　the　high　vacuum　condition　of　similar　to　10(-6)　Pa,　which　the　results　show　that　the　turn-on　field　of　GaN　NWs　changes　from　0.86　to　2.8　V/mu　m　depending　on　their　structures　and　the　current　density　can　reach　up　to　830　mu　A/cm(2)　at　the　field　of　6　V/mu　m.　Combined　the　characterization　results　with　the　work　function　theory　related　to　field　emission,　the　origin　of　the　field　emission　enhancement　was　analyzed,　which　associates　with　their　surface　potential　and　geometric　structure.　These　results　can　enrich　our　knowledge　on　the　field　emission　of　GaN　NWs　and　are　highly　related　to　the　development　of　the　next-generation　of　GaN　nano-electronic　devices.　(C)　2013　Elsevier　B.V.　All　rights　reserved.