This　study　aims　to　realize　biological　phosphorus　removal　using　the　excess　activated　sludge　taken　from　a　wastewater　treatment　plant　in　Beijing.　The　effects　of　carbon　source　on　biological　phosphorus　removal　and　microbial　biomass　maintenance　were　evaluated　with　different　concentrations　and　types　of　carbon　sources,　as　well　as　variations　of　operation　modes　for　a　sequencing　batch　reactor　(SBR),　with　the　appropriate　regulation　on　the　temperature　between　18-24　degrees　C,　initial　pH　level　around　7.5　and　the　dissolved　oxygen　(DO)　concentration　in　the　range　of　2-3　mg/L　at　the　end　of　aerobic　phase.　The　results　showed　that　the　carbon　source　is　a　main　factor　seriously　affecting　the　performance　of　polyphosphate　accumulating　organisms　(PAOs)　for　biological　phosphorus　removal,　and　is　also　crucial　for　the　maintenance　of　microbial　biomass.　The　short-term　aeration　mode　is　in　favor　of　microbial　growth,　and　start-up　of　EBPR　system　can　be　realized　with　the　carbon　source　reasonably　used.