EPS　could　act　as　a　reservoir　for　phosphorus　in　biological　phosphorus　removal　process.　To　better　understand　the　physicochemical　properties　of　EPS　in　the　biological　phosphorus　removal　system,　two　types　of　EPS　taken　from　the　systems　that　operated　complete　aerobically　with　little　phosphorus　removal　ability　(R1)　and　alternative　anaerobically/aerobically　with　excellent　phosphorus　removal　efficiency　(R2)　were　studied.　Results　showed　that　protein　was　predominant　in　the　EPS　of　R2,　while　the　EPS　from　R1　was　dominated　by　polysaccharides.　Protein-like　fluorophores　and　fulvic　acid-like　fluorophores　were　the　main　EEM　spectra　in　both　EPS　types,　whereas　the　fluorescence　intensity　of　protein-like　substances　in　R2　was　higher　than　that　of　R1　at　the　end　of　aerobic　phase.　The　content　of　Ca2+　was　higher　than　Mg2+　in　R1,　while　it　was　opposite　in　R2.　Meanwhile,　the　average　value　of　Ca2+　in　R1　was　8.67mg/g-MLSS,　higher　than　that　of　R2　(2.40mg/gMLSS)　and　the　TP　contents　of　R2　(21.65mg/gMLSS)　was　much　higher　than　that　in　R1　(13.83mg/gMLSS)　at　the　end　of　aeration.　In　addition,　the　zeta　potential　of　R1　(-35mV)　was　more　negative　than　that　in　R2　(-23mV).These　results　demonstrated　that　the　characteristics　of　EBPR　system　was　different　from　the　complete-aerobic　sludge　system.　©,　2014,　Chinese　Society　for　Environmental　Sciences.　All　right　reserved.