In　order　to　improve　the　efficiency　of　sewage　biological　removal　of　nitrogen　and　to　reduce　the　carbon　source　added　from　outside,　the　character　of　simultaneous　nitrification　and　denitrification　of　sequencing　batch　biofilm　reactor　(SBBR)　in　treating　living　sewage　under　the　condition　of　oxygen　existing　was　studied.　Under　the　situation　of　TN　of　raw　water　with　80~110　mg/L　and　dissolved　oxygen　concentration　with　0.8~4.0　mg/L,　the　effluent　TN　was　below　15　mg/L,　NH3~N　removal　rate　reached　100%,　TN　removal　rate　was　54%~77%,　NH3~N　volumetric　load　was　47~94　mg/(L·d),　TN　volumetric　load　was　56~113　mg/(L·d).　Before　NH3~N　reduced　to　zero　or　minimum,　TN　reduced　continuously,　and　after　this　point　raised　for　short　time　then　reduced　slowly.　SBBR　possessed　the　capacity　of　simultaneous　nitrification　and　denitrification　in　wider　range　of　dissolved　oxygen　concentration;　and　when　NH3~N　reduced　to　zero　or　minimun　value,　the　time　was　suggested　to　be　the　end　of　simultaneous　nitrification　and　denitrification.