The　CuO　nanowires　were　successfully　synthesized　by　thermal　oxidation,　and　their　morphologies　and　crystal　structures　were　characterized　by　SEM(scanning　electron　microscopy)　and　XRD(X-ray　diffraction).　The　effect　of　temperature　on　morphologies　and　structures　were　investigated　and　its　growth　mechanism　was　discussed.　The　field　emission　(FE)　measurement　shows　that　the　CuO　nanowries　possess　high　electron　emission　properties.　Its　turn-on　voltage　is　only　3.75　V/μm　and　its　current　density　was　0.33　mA　/cm2.　These　results　suggest　that　the　CuO　nanowire　can　be　an　excellent　FE　material　candidate.　©　2015,　Chongqing　Functional　Materials　Periodical　Press　Co.　Ltd.　All　right　reserved.