To　optimize　the　initiation　of　continuous　flow　CANON　process,　the　research　compared　startup　course　and　nitrogen　removal　performance　under　distinct　NLR　in　room　temperature　((25±1))　between　two　sets　of　AUSB　reactors,　one　of　which　was　middle-setting　aeration　(1#),　and　the　other　was　bottom-setting　aeration　(2#).　The　results　showed　that　1#,　2#　successfully　started　CANON　process　treating　domestic　wastewater　with　relatively　low　ammonium　concentration　(90　mg/L)　in　55　d　and　70　d　respectively.　In　the　progress　of　increasing　nitrogen　loading　rate　gradually,　both　of　them　gained　the　highest　nitrogen　removal　rate,　which　was　0.280　kg/(m3·d)　for　1#,　and　0.256　kg/(m3·d)　for　2#　under　the　condition　of　HRT=6　h.　In　later　operation,　1#　maintained　efficient　nitrogen　removal　status　whose　eigenvalue　(Δρ(TN)/Δρ(NO3--N))　remained　around　7.83,　however,　eigenvalue　of　2#　decreased　to　7.49　after　125　d　operation　owing　to　the　activity　of　NOB　strengthened.　The　middle-setting　aerated　AUSB　accomplished　a　higher　total　nitrogen　removal　rate　which　was　74.98%　through　the　combination　with　simultaneous　nitritation-Anammox　(SNA)　and　alternate　nitritation-Anammox　(ANA)　double　pathways,　which　was　ascribed　to　the　enhancement　of　AOB　and　AnAOB　activity　and　the　effective　suppression　on　NOB.　Middle-setting　aerated　AUSB　could　shorten　starting　period　of　continuous　flow　CANON　process,　and　furthermore　realize　long-term　stable　autotrophic　nitrogen　removal.　©　2018,　Editorial　Board　of　Journal　of　Harbin　Institute　of　Technology.　All　right　reserved.