A　membrane　bioreactor　(MBR)　was　adopted　for　completely　autotrophic　nitrogen　removal　over　nitrite　(CANON)　process　at　ambient　temperature.　CANON　was　rapidly　started-up　within　around　50　d　under　oxygen-limited　condition.　The　average　nitrogen　removal　rate　reached　to　0.70　kg　N　m(-3)　d(-1)　with　a　removal　efficiency　of　88%.　The　ratio　of　air　flow　rate　to　volumetric　ammonium　loading　rate　should　be　maintained　below　0.28　L-air　min(-1)　kg(-1)　N　m(3)　d　for　stable　CANON.　The　feasibility　of　MBR　for　CANON　process　was　proved　in　batch　experiments.　FISH　results　showed　that　aerobic　ammonium-oxidizing　bacteria　predominated　in　the　reactor　sludge,　whereas　anaerobic　ammonium-oxidizing　bacteria　predominated　in　the　membrane　biofilm.　This　study　demonstrated　that　MBR　was　a　suitable　experimental　setup　for　the　operation　of　CANON　process.　(C)　2013　Elsevier　Ltd.　All　rights　reserved.