When　treating　waste　water　with　low　chemical　oxygen　demand　to　ammonium,　the　CANON　process　brings　about　a　striking　innovative　effect.　The　denitrification　performance　of　the　CANON　process　was　studied　by　adopting　the　aeration　up-flow　sludge　bed　reactor　(AUSB).　Under　the　condition　of　ammonia　nitrogen　being　added　as　the　one　and　only　nitrogen　source,　the　reactor　shows　73%　of　the　total　nitrogen　removal　rate.　With　the　gradual　increase　of　inflow　ammonia　nitrogen　and　reduction　of　the　hydraulic　retention　time,　its　denitrification　ability　continues　to　be　promoted　and　the　total　nitrogen　removal　load　reaches　to　more　than　0.47　kg/(m3·d).　By　the　60th　day　since　the　study　began,　the　visible　particles　appeared.　During　the　start-up　period,　the　activity　of　NOB　in　the　system　were　suppressed　effectively,　and　the　value　of　Δρ(TN)/Δρ(NO3--N)　was　close　to　8.　After　the　operation　of　135　d,　the　whole　process　of　autotrophic　denitrification　of　granular　sludge　was　successfully　started　in　a　continuous　flow　reactor.　The　results　demonstrated　that　increasing　the　influent　load　promoted　the　microbial　growth,　thus　a　more　suitable　growth　conditions　for　CANON　strain　was　built　and　NOB　was　gradually　eliminated.　By　the　interaction　of　a　variety　of　biological　populations,　the　reactor　showed　a　high　nitrogen　removal　efficiency,　and　the　continuous　flow　of　CANON　process　started　successfully.　©　2017,　Editorial　Board　of　Journal　of　Harbin　Institute　of　Technology.　All　right　reserved.