The　NH2OH　dosing　strategy　for　nitrogen　removal　was　investigated　in　a　single　return　continuous-flow　anaerobic/aerobic/anoxic/aerobic　(A(n)OAO)　reactor　fed　with　real　municipal　wastewater.　A　high　nitrite　accumulation　ratio　of　98%　was　achieved　in　only　two　days　by　continuously　adding　10　mg/L　NH2OH.　When　gradually　reducing　dosing　frequency　to　one　day　every　four　days,　effluent　total　nitrogen　was　as　low　as　4.8　+/-　2.2　mg　N/L　with　removal　efficiency　of　88.7　+/-　5.3%,　under　aerobic　HRT　of　4.6　h,　DO　below　1.0　mg/L,　and　C/N　of　2.8　without　external　carbon　sources.　Batch　test　showed　that　nitrite　oxidizing　bacteria　(NOB)　activity　decreased　by　81%　after　adding　NH2OH,　while　ammonia　oxidizing　bacteria　(AOB)　activity　remained　stable.　qPCR　confirmed　that　NOB　abundance　decreased,　and　16S　rRNA　sequencing　further　showed　that　g_Nitrospira　belonging　to　NOB　decreased　significantly　(P　＜　0.001).　Overall,　this　study　provides　a　novel　strategy　for　advanced　nitrogen　removal　from　municipal　wastewater　in　continuous　flow　systems.