An　anaerobic　ammonium　oxidation-upflow　anaerobic　sludge　blanket　(anammox-UASB)　reactor　was　operated　without　temperature　control　during　the　four　seasons　and　was　therefore　subjected　to　natural　periodic　temperature　variations　between　9　and　28　degrees　C.　The　anammox　reactor　had　a　high　nitrogen　removal　ability　at　intermediate　and　low　temperatures.　The　total　nitrogen　(TN)　concentration　of　the　influent　increased　from　200　to　1200　mg/L,　the　nitrogen　removal　efficiency　was　maintained　at　90%,　and　the　nitrogen　removal　rate　(NRR)　increased　to　9.15　+/-　0.35　kg　N/m(3)/d.　The　enrichment　of　anammox　bacteria　in　the　UASB　granular　sludge　reached　53.8%,　and　the　dominant　bacteria　changed　from　Candidates　Brocadia　to　Candidates　Kuenenia　after　several　seasons　of　cultivation.　Dynamics　analysis　revealed　that　the　maximum　reaction　rate　of　the　anammox-UASB　sludge　was　62.5　kg　N/m(3)/d,　reflecting　the　high　potential　nitrogen　removal　ability　of　the　reactor.