Due　to　the　fluctuation　of　upstream　sewage　during　the　actual　operation,　the　effect　of　pulsed　inflow　shock　on　the　stability　of　anaerobic　ammonium　oxidation　(ANAMMOX)　process　was　evaluated　in　the　present　study　through　changing　the　amplitude　and　frequency　of　pulsed　inflow.　The　results　showed　that　the　ANAMMOX　process　in　UASB　reactor　had　a　good　adaptivity　and　tolerance　towards　pulsed　inflow　when　the　amplitude　was　less　than　60mL/min(vupflow=1.33cm/min).　Even　through　the　pulsed　frequency　came　to　a　high　level,　the　effluent　could　meet　the　national　1-A　standard.　The　removal　efficiency　ratio　of　NH4+-N　and　NO2--N　could　both　been　kept　above　80%　and　the　removal　ratio　of　total　nitrogen　was　above　70%.　The　process　of　ANAMMOX　in　UASB　reactor　was　unstable　when　the　pulsed　amplitude　came　to　100mL/min　(vupflow=2.22cm/min).　With　the　enhancement　of　pulsed　frequency,　the　adaptation　time　of　ANAMMOX　process　increased.　The　concentrations　of　NH4+-N　and　NO2--N　in　effluent　were　both　above　5mg/L　when　the　pulsed　frequency　came　to　1.5h.　Moreover,　when　the　pulsed　amplitude　increased　from　40mL/min　to　60mL/min　and　100mL/min,　the　abundance　of　anammox　bacteria　in　reactor　and　the　percentage　of　anammox　on　total　bacteria　firstly　increased　and　then　decreased.　The　abundance　and　percentage　of　anammox　bacteria　in　total　bacteria　came　to　the　highest　level　when　the　pulsed　amplitude　came　to　60mL/min.　The　reason　might　be　that　the　mixture　and　contaction　of　the　anammox　and　the　substance　were　more　efficient,　which　facilited　the　growth　of　anammox　bacteria.　©　2016,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.