Adequate　carbon　source　is　critical　for　biological　nutrients　removal　from　wastewater,　and　waste　activated　sludge　(WAS)　treatment　or　disposal　is　costly　and　difficult　in　wastewater　treatment　plants.　In　this　study,　a　novel　sludge　fermentation　process　was　launched　to　develop　the　internal　carbon　source　of　WAS　to　enhance　biological　nitrogen　removal,　nitrite　and　nitrate　was　directly　added　into　anaerobic　fermentation　system　and　then　formed　WAS　anoxic　fermentation　denitrification　system　(AFD),　in　which,　the　sludge　fermentation　and　denitrification　were　expected　to　proceed　simultaneously.　Experimental　results　of　40　days＇　fermentation　showed　that　0.12　gNO(2)(-)-N/gVSS　and　0.11　gNO(3)(-)-N/gVSS,　or　0.26　gNO(2)(-)N/gVSS-reduction　and　0.24　gNO(3)(-)-N/gVSS-reduction,　could　be　simultaneously　obtained　in　AFD,　and　it　could　be　calculated　that　37.9%　of　total　VSS　and　80.7%　of　VSS　reduction　was　utilized　for　nitrite　or　nitrate　removal,　which　suggested　a　good　performance　of　denitrification　driven　by　WAS　in　AFD.　The　highest　accumulation　amount,　204　mg/L,　of　volatile　fatty　acids　was　occurred　in　the　11th　day,　which　proved　a　rapid　fermentation　was　present　in　AFD.　Furthermore,　the　variations　of　pH　or　ORP　in　AFD　could　well　indicate　the　progress　of　fermentation　and　denitrification.