Given　the　carbon　limitation　of　municipal　wastewater,　the　balance　of　biological　nitrogen　and　phosphorus　removal　remains　a　challenging　task.　In　this　study,　an　anaerobic-anoxic-oxic　combining　with　biological　contact　oxidation　(A(2)/O-BCO)　system　treating　real　municipal　wastewater　was　operated　for　205　days,　and　COD-to-PO43--P　ratio　was　confirmed　as　the　key　parameter　for　balancing　denitrifying　phosphorus-accumulating　organisms　(DPAOs)　and　denitrifying　glycogen-accumulating　organisms　(DGAOs)　to　enhance　N　and　P　removal.　When　DPAOs　dominated　in　nutrients　removal,　the　increase　in　COD/P　from　17.1　to　38.1　caused　the　deterioration　in　nitrogen　removal　per-formance　decreasing　to　71.8　%.　As　COD/P　ratio　decreased　from　81.3　to　46.8,　Ca.Competibacter　proliferated　from　3.11　%　to　6.00　%,　contributing　to　58.9　%　of　nitrogen　removal.　The　nitrogen　and　phosphorus　removal　efficiency　reached　up　to　79.3　%　and　95.2　%.　Overall,　establishing　DGAOs-DPAOs　balance　by　strengthening　the　effect　of　DGAOs　could　enhance　the　nutrients　removal　performance　and　accordingly　improve　the　stability　and　efficiency　of　the　system.