Because　the　efficiency　of　biological　nutrient　removal　is　always　limited　by　the　deficient　carbon　source　for　the　low　carbon/nitrogen　(C/N)　ratio　in　real　domestic　sewage,　the　denitrifying　phosphorus　removal　(DNPR)　was　developed　as　a　simple　and　efficient　method　to　remove　nitrogen　and　phosphorous.　In　addition,　this　method　has　the　advantage　of　saving　aeration　energy　while　reducing　the　sludge　production.　In　this　context,　a　pre-denitrification　anaerobic/anoxic/post-aeration　+　nitrification　sequence　batch　reactor　(pre-A(2)NSBR)　system,　which　could　also　reduce　high　ammonia　effluent　concentration　in　the　traditional　two-sludge　DNPR　process,　is　proposed　in　this　work.　The　pre-A(2)NSBR　process　was　mainly　composed　of　a　DNPR　SBR　and　a　nitrifying　SBR,　operating　as　alternating　anaerobic/anoxic/post-aeration　+　nitrification　sequence.　Herein,　the　long-term　performance　of　different　nitrate　recycling　ratios　(0-300%)　and　C/N　ratios　(2.5-8.8),　carbon　source　type,　and　functional　microbial　community　were　studied.　The　results　showed　that　the　removal　efficiency　of　total　inorganic　nitrogen　(TIN,　including　NH4+　-N,　NO2-　-N,　and　NO3-　-N)　gradually　increased　with　the　nitrate　recycling　ratios,　and　the　system　reached　the　highest　DNPR　efficiency　of　94.45%　at　the　nitrate　recycling　ratio　of　300%.　The　optimum　C/N　ratio　was　around　3.9-7.3　with　a　nitrogen　and　phosphorus　removal　efficiency　of　80.15%　and　93.57%,　respectively.　The　acetate　was　proved　to　be　a　high-quality　carbon　source　for　DNPR　process.　The　results　of　fluorescence　in　situ　hybridization　(FISH)　analysis　indicated　that　nitrifiers　and　phosphorus　accumulating　organisms　(PAOs)　were　accumulated　with　a　proportion　of　19.41%　and　26.48%,　respectively.　(c)　Higher　Education　Press　and　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature　2018