The　effect　of　ammonium　concentrations　on　the　anaerobic　ammonium　oxidation　(Anammox)　activity　of　simultaneous　partial　nitrification,　anaerobic　ammonium　oxidization　and　denitrification　(SNAD)　biofilm　was　investigated　in　batch　tests.　The　SNAD　biofilm　reactor　performed　stable　nitrogen　removal　performance　with　the　influent　of　domestic　wastewater.　The　average　influent　NH4+-N　and　COD　concentrations　were　70mg/L　and　180mg/L,　respectively.　As　a　result,　the　average　effluent　NH4+-N,　NO2--N　and　NO3--N　concentrations　were　2mg/L,　2mg/L,　7mg/L　and　50mg/L,　respectively.　The　SNAD　biofilm　performed　good　Anammox　activity.　The　NH4+-N,　NO2--N　and　total　inorganic　nitrogen　(TIN)　removal　rates　were　0.121kg　N/(kg　VSS·d),　0.180kg　N/(kg　VSS·d)　and　0.267kg　N/(kg　VSS·d)　with　the　initial　NH4+-N　and　NO2--N　concentrations　of　both　70mg/L.　Moreover,　Haldane　model　was　applied　to　investigate　the　ammonium　inhibition　on　the　Anammox　process.　There　is　no　obvious　difference　in　kinetic　coefficients　of　ammonium　inhibition　under　high　or　low　FA　conditions.　As　for　M1　(FA　ranges　of　0.7mg/L　and　20.4mg/L),　the　rmax,　Ks　and　KI　of　ammonium　were　0.209kg　NO2--N/(kg　VSS·d),　9.5mg/L　and　422mg/L.　As　for　M2　(FA　ranges　of　6.3mg/L　and　190.5mg/L),　the　rmax,　Ks　and　KI　of　ammonium　were　0.221kg　NO2--N/(kg　VSS·d),　6.1mg/L　and　597mg/L.　Ammonium　rather　than　FA　is　the　main　inhibitor　for　Anammox　process.　©　2016,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.