A　simple　method　to　detect　the　concentration　of　multiwall　carbon　nanotubes　(MWNTs)　and　Mg(NO3)(2)　in　electrophoretic　suspension　was　developed.　It　consists　of　UV-vis　absorbance　spectrophotometry　for　MWNTs　and　conductivity　test　for　Mg2+.　The　obtained　linear　calibration　curves　were　used　to　determine　the　amount　of　MWNTs　and　Mg2+　in　the　electrophoretic　suspension.　Furthermore,　the　morphologies,　field　emission　properties　and　compositions　of　the　electrophoretic　deposited　MWNTs　films　from　suspension　were　investigated　in　detail.　The　results　showed　that　the　optimized　concentration　of　MWNTs　and　Mg(NO3)(2)　were　0.12　g/L　and　0.20　mmol/L　in　MWNTs　electrophoretic　suspension,　respectively.　Under　the　optimum　conditions,　the　turn-on　field　of　MWNTs　cathode　was　0.90　V/mu　m　and　the　maximum　emission　current　density　was　2.90　mA/cm(2).　(C)　2013　Elsevier　B.V.　All　rights　reserved.