The　performance　of　nitrogen　removal　from　municipal　wastewater　was　investigated　in　Anoxic/Oxic(A/O)+　Anammox　(anoxic　ammonium　oxidation)　system.　The　results　show　that　total　nitrogen　(TN)　can　be　effectively　removed　from　municipal　wastewater　in　A/O+Anammox　system.　The　effluent　TN　and　NH4+-N　concentrations　are　11.48　mg/L　and　1.83　mg/L　in　average,　respectively,　when　the　influent　TN　concentration　is　62.01　mg/L　and　the　ratio　of　soluble　chemical　oxygen　demand　(SCOD)　to　TN　is　2.42.　The　TN　removal　in　A/O　reactor　contributes　to　51.13%　of　TN　removal　in　A/O+Anammox　system,　which　is　achieved　through　denitrification,　simultaneous　nitrification　and　denitrification　and　waste　biomass　discharge.　The　nitrite-to-ammonium　ratio　of　the　effluent　from　the　A/O　reactor　can　be　controlled　at　about　1.0,　which　is　beneficial　to　the　Anammox　reaction.　48.87%　of　TN　removed　from　municipal　wastewater　is　due　to　Anammox　reaction　in　the　Anammox　reactor.　So　partial　nitritation　and　anoxic　ammonium　oxidation　is　the　key　point　for　high　TN　removal　efficiency　of　A/O+Anammox　system　in　treating　low　C/N　municipal　wastewater.