The　start-up　period　of　anaerobic　ammonium　oxidation　(ANAMMOX)　reactor　usually　took　more　than　100　d　which　restrained　the　application　of　ANAMMOX　process　in　domestic　wastewater　treatment.　The　fast　start-up　of　anaerobic　ammonium　oxidation(ANAMMOX)　granular　reactor　was　investigated　under　high　up-flow　velocity　(5　m/h)　when　the　ammonium　and　nitrite　mass　concentrations　of　the　influent　were　20　mg/L　and　26　mg/L,　respectively.　The　results　shows　that　the　nitrogen　removal　rate　of　ANAMMOX　reactor　reaches　4.08　kg·m-3·d-1　on　60　d　which　indicates　the　successful　start-up　of　ANAMMOX　reactor.　During　the　stable　operation　period,　the　average　nitrogen　removal　rate　reaches　4.3　kg·m-3·d-1and　the　average　ammonium　and　nitrite　removal　efficiencies　reach　99.3%　and　98.8%,　respectively.　The　granules　obtained　from　ANAMMOX　reactor　are　rufous　in　color　and　the　majority　(79.3%)　diameter　of　granules　is　in　the　range　of　0.5-0.9　mm　on　100　d.　The　abundance　of　ANAMMOX　in　up-flow　Anaerobic　sludge　bed　(UASB)　reactor　was　also　investigated　by　q-PCR.　The　results　show　that　the　concentration　of　ANAMMOX　bacteria　is　much　higher　in　the　bottom　of　UASB　reactor　which　reaches　1.28×1011　copy　numbers·gMLVSS-1.　©,　2014,　Central　South　University　of　Technology.　All　right　reserved.