Simultaneous　partial　nitrification,　biological　phosphorous　removal　and　sludge　fermentation　in　continuous-flow　system　faced　many　challenges　in　wastewater　treatment　plants　(WWTPs).　In　this　study,　a　novel　process　was　developed　to　achieve　partial　nitrification,　enhanced　biological　phosphorus　removal　and　in-situ　fermentation　(PNPRF)　in　continuous-flow　system　dominated　by　Tetrasphaera　treating　low　carbon/nitrogen　ratio　(COD/N)　real　domestic　wastewater.　After　80　days　of　operation,　no　external　carbon　was　added　into　the　influent.　Nitrite　accumulation　ratio　(NAR)　reached　99.4%　and　removal　efficiency　of　PO43-　-P　was　100%.　The　effluent　concentration　of　total　inorganic　nitrogen　(TIN)　was　lower　than　2　mg/L.　Compared　with　traditional　biological　nitrogen　and　phosphorus　removal　processes,　the　daily　sludge　discharge　in　continuous-flow　PNPRF　decreased　by　61.9%.　DNA　concentration　of　the　sludge　supernatant　after　anaerobic　zone　was　2.26-fold　of　that　before　anaerobic　zone,　and　percentages　of　intact　cells　decreased　by　6.9%　and　necrotic　cells　increased　by　8.3%,　indicating　that　cell　lysis　caused　the　reduction　of　sludge　discharge.　The　negative　effect　of　prolonged　anaerobic　phase　on　transcriptional　response　of　nxrB　gene　was　more　significant　than　that　of　amoA　and　hao　gene,　which　resulted　in　stable　partial　nitrification.　The　activities　of　ammonium-oxidizing　bacteria　(AOB)　were　higher　than　that　of　nitrite-oxidizing　bacteria　(NOB),　and　reverse　transcriptional　PCR　(RT-PCR)　showed　that　RNA　expression　of　AOB　was　higher　than　that　of　NOB.　Achieving　partial　nitrification,　enhanced　biological　phosphorus　removal　and　in-situ　fermentation　in　continuous-flow　system　dominated　by　Tetrasphaera　solved　the　problems　of　carbon　source　deficiency　and　large　amount　of　sludge　discharge　in　treating　real　domestic　wastewater　process.