Temperature　is　an　important　physical　factor,　which　strongly　influences　biomass　and　metabolic　activity.　In　this　study,　the　effects　of　temperature　on　the　anoxic　metabolism　of　nitrite　(NO2-)　to　nitrous　oxide　(N2O)　by　polyphosphate　accumulating　organisms,　and　the　process　of　the　accumulation　of　N2O　(during　nitrite　reduction),　which　acts　as　an　electron　acceptor,　were　investigated　using　91%　+/-　4%　Candidatus　Accumulibacter　phosphatis　sludge.　The　results　showed　that　N2O　is　accumulated　when　Accumulibacter　first　utilize　nitrite　instead　of　oxygen　as　the　sole　electron　acceptor　during　the　denitrifying　phosphorus　removal　process.　Properties　such　as　nitrite　reduction　rate,　phosphorus　uptake　rate,　N2O　reduction　rate,　and　polyhydroxyalkanoate　degradation　rate　were　all　influenced　by　temperature　variation　(over　the　range　from　10　to　30　degrees　C　reaching　maximum　values　at　25　degrees　C).　The　reduction　rate　of　N2O　by　N2O　reductase　was　more　sensitive　to　temperature　when　N2O　was　utilized　as　the　sole　electron　acceptor　instead　of　NO2,　and　the　N2O　reduction　rates,　ranging　from　0.48　to　3.53　N2O-N/(hr.g　VSS),　increased　to　1.45　to　8.60　mg　N2O-N/(hr.g　VSS).　The　kinetics　processes　for　temperature　variation　of　10　to　30　degrees　C　were　(theta(1)　=　1.140-1.216　and　theta(2)　=　1.139-1.167).　In　the　range　of　10　degrees　C　to　30　degrees　C,　almost　all　of　the　anoxic　stoichiometry　was　sensitive　to　temperature　changes.　In　addition,　a　rise　in　N2O　reduction　activity　leading　to　a　decrease　in　N2O　accumulation　in　long　term　operations　at　the　optimal　temperature　(27　degrees　C　calculated　by　the　Arrhenius　model).