The　removal　effect　of　main　pollutant　which　was　in　the　wastewater　of　expressway　service　area　was　investigated　in　the　up-flow　biological　aerated　filter　(UBAF)　with　different　hydraulic　loadings.　The　result　showed　that　with　the　increase　of　hydraulic　loading,　the　removal　rates　of　the　chemical　oxygen　demand　COD　and　turbidity　decreased.　At　hydraulic　loading　of　0.5　m3(/)(m(2).h),　removal　rates　of　COD　and　turbidity　were　79.6%　and　80.2%　respectively,　which　were　better　than　that　of　56.5%　and　48.7%　at　hydraulic　loading　of　1.25　m(3)/(m(2).h).