The　impact　of　different　aeration　positions　on　startup　and　operation　of　the　continuous　flow　CANON　granular　sludge　process　was　considered　by　inoculating　flocculent　ANAMMOX　activated　sludge　at　room　temperature　(25±1)　in　two　sets　of　AUSB　reactors.　The　aeration　unit　of　R1　was　installed　0.3　m　above　the　base,　while　the　aeration　unit　of　R2　was　set　at　the　bottom.　R1　and　R2　successfully　developed　the　granule　CANON　process　on　the　43rd　d　and　56th　d,　respectively.　The　mean　particle　diameter　of　R1　granular　sludge　increased　to　214.79　μm,　and　the　eigenvalue　(ΔNO3--N/ΔTN)　was　maintained　at　0.128;　whereas,　the　granular　sludge　size　of　R2　rose　to　205.27　μm　with　an　eigenvalue　maintained　at　0.129.　The　nitrogen　loading　rate　(NLR)　was　gradually　increased　in　the　low　ammonia-nitrogen　(90　mg•L-1)　wastewater　within　R1　and　R2.　This　was　more　beneficial　in　R1,　resulting　in　the　persistent　growth　of　CANON　granular　sludge　and　the　enhancement　of　the　systematic　nitrogen　removal　rate　(NRR).　The　average　particle　diameter　of　R1　rose　to　507.46　μm　in　88　d,　while　NRR　reached　up　to　0.277　kg•(m3•d)-1.　R2　granule　sludge　particle　size　was　467.72　μm　after　108　d　of　cultivation,　and　achieved　a　0.243　kg•(m3•d)-1NRR,　which　was　87.73%　of　that　in　R1.　During　the　course　of　steady　operation,　the　specific　anoxic/aerobic　mode　of　R1　effectively　suppressed　NOB　microbial　activity,　the　eigenvalue　remained　around　0.127±0.003,　and　the　NRR　of　R1　was　maintained　at　about　(0.262±0.019)　kg•(m3•d)-1.　However,　NOB　was　propagated　observably　in　the　continuously　aerobic　R2,　whose　eigenvalue　rose　to　0.136±0.004,　while　NRR　was　merely　(0.231±0.015)　kg•(m3•d)-1　after　125　d　of　long-term　operation.　During　the　whole　experiment　period,　the　intermediate-setting　aerated　AUSB　accelerated　the　formation　of　CANON　granular　sludge　evolving　from　flocculent　ANAMMOX　sludge,　and　better　nitrogen　removal　performance　and　operational　stability　were　achieved.　©　2018,　Science　Press.　All　right　reserved.