Zinc　oxide　(ZnO)　nanopillars　on　a　ZnO　seed　layer　and　ZnO　nanoflowers　were　synthesized　by　electrochemical　deposition　on　linear　wires.　The　morphologies　and　crystal　orientation　of　the　ZnO　nanostructures　were　investigated　by　a　scanning　electron　microscopy　and　an　X-ray　diffraction　pattern,　respectively.　Detailed　study　on　the　field-emission　properties　of　ZnO　nanostructures　indicates　that　nanopillars　with　a　high　aspect　ratio　show　good　performance　with　a　low　turn-on　field　of　0.16　V/μm　and　a　high　field　enhancement　factor　of　2.86　×　104.　A　luminescent　tube　with　ZnO　nanopillars　on　a　linear　wire　cathode　and　a　transparent　anode　could　reach　a　luminance　of　about　1.5　×　10　4　cd/m2　under　an　applied　voltage　of　4　kV.　©　2012　Chinese　Institute　of　Electronics.