The　purification　treatment　of　carbon　nanotubes-alumina　was　carried　out　using　various　oxidizers　(ox),　such　as　H2O2,　concentrated　HNO3,　and　air.　The　obtained　composite　was　used　as　support　for　ruthenium　catalysts.　The　structures　and　properties　of　the　products　before　and　after　modification　were　characterized　and　measured　using　transmission　electron　microscopy　(TEM),　thermogravimetric　analysis　(TG),　X-ray　diffraction　(XRD),　and　Fourier　transform　infrared　(FTIR)　spectroscopy.　The　results　show　that　purification　modification　treatment　can　remove　the　impurities　on　the　surface　of　the　CNTs-alumina,　shorten　the　CNTs,　and　increase　the　amounts　of　hydroxyl,　carboxyl,　and　carbonyl　groups.　Inductively　coupled　plasma　(ICP)　analysis　shows　that　the　dissolution　solution　composition　of　the　CNTs-alumina　composite　supports　with　HNO3　oxidation　treatment　contains　49.98　mg·g-1　Al.　The　ammonia　synthesis　rate　of　the　Ru/　CNTs-alumina-H2O2　was　found　to　be　39.8　mmol·g-1·h-1　at　10　MPa,　10000　h-1,　and　425　°C,　which　was　higher　than　those　for　other　CNTs-alumina-ox　supported　Ru　catalysts.　©　Editorial　office　of　Acta　Physico-Chimica　Sinica.