The　impact　of　nitrite(44.64,　70.3,　94.33,　112.36　mg　NO2--N·L-1)on　denitrifying　phosphorus　removal　metabolism　was　investigated　by　using　92%±3%　polyphosphate　accumulation　organisms　domesticated　in　acetate/propionic　acid　for　340　d.　The　results　showed　that　denitrifying　phosphorus　removal　metabolism　also　occurred　when　nitrite　was　used　as　electron　acceptor　at　first,　and　the　metabolism　was　inhibited　when　the　concentration　of　nitrite　increased.　Nitrite　reduction　rate,　phosphorus　uptake　rate　and　PHA　degradation　rate　all　reduced　with　initial　nitrite　increasing,　and　the　complete　inhibition　concentration　was　higher　than　112.36　mg　NO2--N·L-1.　Nitrite　reduction　rate　and　phosphorus　uptake　rate　were　2.61　mg　NO2--N·(g　MLSS)-1·h-1　and　3.0　mg　PO43--P·(g　MLSS)-1·h-1　at　initial　112.36　mg　NO2--N·L-1.　N2O　was　produced　in　the　denitrifying　phosphorus　removal　process.　Initial　nitrite　stimulated　nitrite　reduction　to　exceed　N2O　reduction　rate,　resulting　in　greater　quantities　of　N2O　production.　The　proportion　of　N2O-N/TN　were　63.5%,　49.0%,　30.2%,　24.0%　respectively　corresponding　to　initial　concentration　of　44.64,　70.3,　94.33,　112.36mg　NO2--N·L-1.　The　accumulation　of　N2O　could　be　transformed　to　N2　in　order　to　improve　denitrification　when　the　system　had　enough　substrate　and　extended　anoxic　mixing　time.