In　this　study,　a　simultaneous　partial　nitrification　and　phosphorus　removal-anaerobic　ammonia　oxidation　(SPNPR-A)　system　with　short-cycle　and　low-concentration　nitrite　(NO2--N)　was　established.　The　SPNPR　system　operates　in　anaerobic/aerobic　mode,　and　the　NO2--N　concentration　in　the　system　was　limited　for　a　brief　duration　to　restrict　nitrite　oxidizing　bacteria　(NOB),　simultaneously　enriching　ammonia　oxidizing　bacteria　(AOB)　and　polyphosphate　accumulating　organisms　(PAOs),　and　finally　realizing　synchronous　nitrogen　and　phosphorus　removal.　The　results　showed　that　the　NOB　activity　could　be　effectively　inhibited　by　maintaining　the　NO2--N　concentration　in　the　SPNPR　system　at　about　10mg/L　for　a　short-cycle.　After　70days,　the　nitrite　accumulation　rate　(NAR)　of　the　two　short-cycles　of　SPNPR　system　reached　90.40%　and　88.93%,　respectively,　and　the　average　removal　rates　of　total　nitrogen　(TN),　total　phosphorus　(TP)　and　chemical　oxygen　demand　(COD)　in　SPNPR-A　system　were　87.45%,　84.30%　and　94.26%,　respectively.　At　the　60th　day,　specific　ammonia　oxidation　rate　(SAOR)　and　specific　oxygen　utilization　rateAOB　(SOURAOB)　were　8.47mgN/(gMLVSS·h)　and　12.71mgO2/(gMLVSS·h),　respectively.　Specific　nitrate　production　rate　(SNPR)　and　specific　oxygen　utilization　rateNOB　(SOURNOB)　were　0.82mgN/(gMLVSS·h)　and　0.41mgO2/(gMLVSS·h),　respectively.　The　results　of　high-throughput　sequencing　showed　that,　the　abundance　of　AOB　genera　Nitrosomonas　(6.46%)　and　Nitrosospira　(0.64%)　in　SPNPR　system　was　much　higher　than　that　of　NOB　genera　Nitrospira　(0.14%)　and　Nitrobacter　(0.01%)　on　the　70th　day,　and　at　the　same　time,　the　phosphate　accumulating　organisms　of　Candidatus_Accumulibacter　(1.61%)　and　Tetrasphaera　(0.89%)　were　gradually　enriched,　so　that　the　SPNPR-A　system　underscored　the　robust　performance　of　synchronous　nitrogen　and　phosphorus　removal.　©　2024　Chinese　Society　for　Environmental　Sciences.　All　rights　reserved.