Nitrite　has　been　commonly　recognized　as　an　important　factor　causing　N2O　production,　which　weakened　the　advantages　of　nitrogen　removal　via　nitrite.　To　reduce　and　control　N2O　production　from　wastewater　treatment　plants,　both　long-term　and　batch　tests　were　carried　out　to　investigate　main　sources　and　pathways　of　N2O　production　during　nitrogen　removal　via　nitrite　from　real　domestic　wastewater.　The　obtained　results　showed　that　N2O　production　during　nitrogen　removal　via　nitrite　was　1.5　times　as　much　as　that　during　nitrogen　removal　via　nitrate.　It　was　further　demonstrated　that　ammonia　oxidization　were　main　source　of　N2O　production　during　nitrogen　removal　from　domestic　wastewater;　whereas,　almost　no　N2O　Was　produced　during　nitrite　oxidization　and　anoxic　denitrification.　N2O　production　during　nitrogen　removal　via　nitrite　decreased　about　50%　by　applying　the　step-feed　SBR,　due　to　the　effective　control　of　nitrite　and　ammonia,　the　precursors　of　N2O　production.　Therefore,　the　step-feed　system　is　recommended　as　an　effective　method　to　reduce　N2O　production　during　nitrogen　removal　via　nitrite　from　domestic　wastewater.