The　performance　of　biofilm　reactor　with　30%　filling　rate　of　polyethylene　K3　filler　was　studied　for　the　treatment　of　domestic　wastewater　in　operating　temperature　at　20　degrees　C　and　10　degrees　C,　respectively.　The　reactor　ran　in　SBR　mode,　compare　the　removal　efficiency　of　pollutants　in　the　reactor　under　two　different　temperature,　the　removal　efficiency　of　COD,　NH4+-N,　TN　and　TP　at　20　degrees　C　were　90%,　70%,　70%　and　80%,　respectively.　It　was　higher　than　at　10　degrees　C.　Analysis　of　biofilm　characteristics　indicated　that　biomass　was　less　affected　by　temperature,　DHA　and　SOUR　were　1.76　g/gMLVSS　and　18.13　mgO(2)/gMLSS*h　at　10　degrees　C,　which　was　5.07　g/gMLVSS　and　63.8　mgO(2)/gMLSS*h　at　20　degrees　C,　respectively.　Temperature　mainly　affects　the　activity　of　microorganisms　on　biofilms.