In　this　study,　domestic　sewage　was　utilized　to　cultivate　aerobic　granular　sludge　(AGS)　in　a　simultaneous　nitrogen　and　phosphorus　removal　(SNPR)　system.　The　bacterial　population　dynamics　during　the　aerobic　sludge　granulation　were　investigated　to　reveal　the　granulation　mechanisms　using　Illumina　MiSeq　PE300　high-throughput　sequencing.　Quantitative　real　time　polymerase　chain　reactions　(PCR)　were　used　to　investigate　shifts　in　the　abundance　of　ammonia-oxidizing　bacteria　(AOB),　ammonia-oxidizing　archaea　(AOA),　nitrite-oxidizing　bacteria　(NOB)　and　polyphosphate　accumulating　organisms　(PAOs).　After　cultivation　for　100　d,　the　AGS　was　compact　and　demonstrated　good　SNPR　performance.　During　the　AGS　formation　process,　extracellular　polysaccharides　obviously　increased,　while　extracellular　proteins　kept　relatively　stable.　The　abundance　of　AOA　significantly　decreased　during　the　formation　of　AGS　process,　while　the　abundance　of　PAOs　increased.　The　bacterial　diversity　increased　at　first　and　then　decreased　during　the　formation　of　AGS.　The　bacterial　community　changed　dramatically　during　aerobic　sludge　granulation.　Persistent　operational　taxonomic　units　(OTUs)　accounted　for　92.70%　of　the　total　sequences.　Proteobacteria　(31.07%-53.67%),　Bacteroidetes　(6.70%-16.50%)　and　Chloroflexi　(7.84%-13.36%)　were　the　dominant　phyla.　Candidatus　competibacter　was　obviously　enriched　in　the　AGS　formation　process　(increased　from　0.11%　in　the　seed　sludge　to　35.33%　in　the　AGS)　and　may　play　an　important　role　in　the　formation　of　AGS.　©　2017,　Science　Press.　All　right　reserved.