Aerobic　granular　sludge　(AGS)　for　simultaneous　nitrogen　and　phosphorus　removal　(SNPR)　was　cultivated　and　studied　in　two　lab-scale　sequencing　batch　reactors　(named　as　A　&　B)　treating　real　domestic　wastewater,　additional　carbon　(sodium　propionate　and　sodium　acetate　for　A,　glucose　for　B)　was　added　to　make　the　ratio　of　COD:N:P　as　360:60:6,　good　SNPR　was　achieved　at　normal　(18-27　degrees　C)　and　low　temperature　(9-13　degrees　C).　The　microbial　community　composition　and　distribution,　distribution　of　cells　and　extracellular　polymeric　substances　(EPS)　and　morphologies　of　the　AGS　were　investigated　using　fluorescence　in　situ　hybridization　(FISH),　in　situ　fluorescent　staining　and　scanning　electron　microscope　(SEM),　respectively.　FISH　results　showed　that　ammonium-oxidizing　bacteria　comprised　12%　of　all　the　bacteria　and　were　mainly　located　at　the　outer　parts　of　the　granules;　phosphates　accumulating　organisms　comprised　40%　of　all　the　bacteria　and　were　mainly　located　in　the　inner　parts　of　the　granules.　Nitrification　was　the　rate　controlling　step;　denitrifying　phosphate　accumulating　organisms　inside　the　granular　sludge　might　be　responsible　for　denitrification　in　the　aerobic　phase,　which　enabled　effective　SNPR.　Live/dead　fluorescent　staining　results　showed　that　dead　cells　were　distributed　throughout　the　granules　and　live　cells　were　principally　distribution　of　polysaccharide　(including　alpha-mannopyranosyl,　alpha-glucopyranosyl　sugars　and　beta-D-glucopyranose　polysaccharides)　of　EPS　in　AGS　were　influenced　by　different　carbon　sources,　but　the　contents　and　distributions　of　protein　and　lipids　were　not,　the　contents　of　protein　was　the　largest.　Polysaccharide　was　responsible　for　the　formation　and　maintenance　of　aerobic　granular　sludge.　SEM　results　showed　that　bacilli　and　cocci　were　the　main　bacteria　in　the　granules　of　A　and　B,　respectively.　Carbon　sources　affected　the　bacteria　type　and　the　SNPR　efficiency,　sodium　propionate　and　sodium　acetate　were　better　than　glucose.