The　influence　of　carbon　and　alternating　oxic-anoxic　model　on　sludge　bulking　and　chemical　oxygen　demand　(COD),　ammonia　nitrogen　and　total　nitrogen　removal　effect　are　investigated　under　alternating　oxic-anoxic　model　in　sequencing　batch　reactor　(SBR).　The　experiment　performed　for　23　days　and　30　days　instage　1　and　2　separately.　The　results　showed　that　the　average　removal　rate　of　ammonia　nitrogen,　total　nitrogen　and　COD　were　97.8%,　68.1%　and　55.1%　in　stage　1.　The　average　removal　rate　of　total　nitrogen　improved　to　90.4%　in　stage　2　mainly　due　to　that　the　addition　of　carbon　source　and　more　electron　accepter,　more　nitrate　and　nitrite　were　reduced　to　nitrogen,　The　removal　of　COD　reached　82.5%　due　to　the　addition　of　sodium　acetate　and　the　increasement　of　organic　loading,　at　last　the　effluent　met　the　national　level　A　standard.　The　MLSS　maintained　steadily　around　3000mg/L　in　stage　1　and　2,　the　SVI　improved　slowly　and　reached　180　ml/g　at　the　end　during　stage　2,　the　inflow　water　got　high　concentration　of　small　molecular　compounds　by　addition　of　sodium　acetate　which　was　favor　of　increasement　of　filamentous　bacterium,　the　SVI　was　affected　by　the　amount　of　filamentous　bacterium.