A　CANON　reactor　with　modified　polyethylene　carrier　was　started　up　by　seeding　sludge　from　another　mature　CANON　reactor　and　using　artificial　inorganic　ammonia-rich　waste　water　as　influent.　To　accelerate　ANAMMOX　bacteria　cultivation,　the　start-up　was　under　anaerobic　conditions　first　to　avoid　dissolved　oxygen　inhibition　on　ANAMMOX　bacteria,　and　then　under　aerobic　conditions.　The　reactor　was　first　under　anaerobic　conditions　to　start　ANAMMOX　process　at　room　temperature　[(20±5)]　in　first　300　days,　however,　total　nitrogen　removal　load　was　only　0.12　kg·(m3·d)-1,　which　meant　failure　of　ANAMMOX.　When　temperature　was　increased　to　30,　30　days　later,　total　nitrogen　removal　load　was　up　to　0.23　kg·(m3·d)-1.　Then　anaerobic　conditions　was　changed　to　aerobic　conditions,　and　total　nitrogen　removal　load　was　up　to　1.01　kg·(m3·d)-1,　while　nitrogen　removal　efficiency　was　77.61%,　and　average　variation　ratio　of　nitrate　and　nitrogen　(δNO3--N/δTN)　was　0.122,　close　to　theoretical　value　0.127,　showing　both　good　stability　of　nitritation　and　good　nitrogen　removal.　Adopting　the　way　of　anaerobic　stage　first　and　then　aerobic　stage　could　not　accelerate　ANAMMOX　bacteria　cultivation　as　expected,　and　modified　polyethylene　carrier　was　not　a　suitable　carrier　to　start　ANAMMOX　process　under　anaerobic　conditions.　However,　once　the　reactor　was　successfully　started　up,　aeration　could　be　saved,　though　it　might　perform　unstably.　Modified　polyethylene　carrier　was　suggested　to　combine　with　UASB　reactor　to　keep　bacteria.　©All　Rights　Reserved.