Nitric　acid　treatment　of　CNTs-cordierite　monolith　changes　the　amount　of　Mg,　Si,　Al　and　oxygen-containing　functional　groups,　thereby　influencing　on　the　surface　area　and　pore　size　distribution　of　composite　materials.　Appropriate　treatment　of　CNTs-cordierite　with　nitric　acid　increases　the　surface　area　and　the　amount　of　micropores　slightly,　but　improves　the　activities　for　ammonia　synthesis　noticeable,　which　might　be　a　consequent　of　the　variation　of　the　amount　of　Mg,　Si,　Al　and　oxygen-containing　functional　groups.　The　ammonia　synthesis　activity　of　Ba-Ru/CNTs-cordierite　increase　by　more　than　30%　if　the　support　material　is　treated　at　30　°C　for　4　h　with　nitric　acid.　©　2008　Springer　Science+Business　Media,　LLC.