The　present　paper　aims　to　introduce　research　of　the　effect　of　organic　carbon　on　the　denitrogenation　using　simultaneous　nitrification　and　denitrification　in　moving-bed　biofilm　reactor.　COD/TN　ratio　was　about　3　in　real　domestic　wastewater.　The　result　of　the　treatment　show　that　at　the　end　of　aeration　the　average　removing　rate　of　TN,　NH4+-N　and　COD　can　reach　59.8%,　83.12%　and　94.9%,　respectively.　In　order　to　improve　the　efficiency　of　removing　TN,　the　experiment　added　amylum,　glucose　and　methanol.　The　results　show　that　adding　organic　carbon　can　improve　the　degradation　of　COD　and　nitrogen.　When　adding　amylum,　COD　degradation　was　incomplete　and　leaded　to　the　system　performance　deterioration.　When　adding　methanol　and　glucose,　the　TN　removal　ratio　reached　84.5%　and　80.55%,　respectively.　But　considering　factors　of　security　and　economy,　adding　glucose　is　more　appropriate.