The　rapid　start-up　and　advanced　nutrient　removal　of　simultaneous　nitrification,　endogenous　denitrification,　and　phosphorus　(P)　removal　aerobic　granular　sequence　batch　reactor　(SNEDPR-AGSBR)　is　a　challenge　in　the　treatment　of　low　carbon/nitrogen　(C/N)　domestic　sewage.　In　this　study,　the　feasibility　of　the　SNEDPR-AGSBR　process　was　examined　in　an　exceedingly　single-stage　anaerobic/aerobic/anoxic　sequencing　batch　reactor　for　treating　low　C/N　ratio　(3.3-5.0)　domestic　sewage.　The　initial　results　showed　that　accompanied　by　the　rapid　formation　of　the　mature　aerobic　granular　sludge　based　on　the　selection　for　slow-growing　organisms,　the　rapid　start-up　(38　d)　of　the　SNEDPR-AGSBR　process　was　successfully　realized.　The　formed　mature　aerobic　granules　had　a　dense　structure　with　an　average　diameter　of　667.7　mu　m　and　SVI30　of　30.0　mL/g.　Two　conditions　for　achieving　the　competitive　balance　between　phosphorus-accumulating　organisms/denitrifying　phosphorus-accumulating　organisms　(PAOs/　DPAOs)　and　glycogen　accumulating　organisms/denitrifying　glycogen　accumulating　organisms　(GAOs/DGAOs)　were　revealed　by　the　long-term　operation　results.　First,　the　dissolved　oxygen　(DO)　concentration　needed　to　be　decreased　to　3.0　mg/L　in　the　aerobic　phase,　and　then,　the　aerobic　and　anoxic　phase　hydraulic　retention　time　(HRT)　should　be　increased　to　3.0　h.　Notably,　high　removal　efficiencies　for　NH+4　-　N　(100%),　total　nitrogen　(84.3%),　and　P　(91.8%)　of　the　SNEDPR-AGSBR　process　were　stably　obtained　with　a　low　C/N　ratio　of　3.9　domestic　sewage.　Simultaneous　nitrification　and　endogenous　denitrification　(SNED)　efficiency　of　61.6%　was　achieved　during　a　long-term　operation　of　142　days.　Finally,　microbial　community　analysis　confirmed　that　GAOs　(Defluviicoccus)/DGAOs　(Candidatus_Competibacter)　were　responsible　for　the　removal　N,　and　PAOs　(Acinetobacter,　Candidatus_Accumulibacter,　Hypomicrobinm)/DPAOs　(Pseudomonas　and　Dechloromonas)　ensured　P　removal.