CeO2　modified　V2O5/AC　catalysts　(V-Ce/AC)　were　synthesized　by　an　ultrasound-assisted　impregnation　method,　and　were　employed　to　remove　elemental　mercury　(Hg-0)　from　simulated　coal　combustion　flue　gas　at　low　temperature　(100-200　degrees　C).　The　effects　of　several　operation　conditions,　including　the　loading　of　CeO2,　reaction　temperature,　the　role　of　O-2　and　stability　of　the　catalysts　were　all　investigated,　respectively.　The　results　showed　that　1　V-8Ce/AC　catalysts　had　the　highest　catalytic　activity　with　98.3%　Hg-0　removal　efficiency　at　150　degrees　C.　There　was　synergistic　effect　on　Hg-0　oxidation　when　V2O5　and　CeO2　combined.　Characterization　by　XPS,　we　found　that　both　lattice　oxygen　(O-alpha)　and　chemisorption　oxygen　(O-beta)　contribute　to　Hg-0　oxidation.　Besides,　the　possible　mechanism　of　Hg-0　removal　over　the　catalysts　was　proposed,　in　which　the　critical　steps　were　the　adsorption　of　Hg-0　and　the　oxidation　of　Hg-0　to　Hg2+　by　the　active　oxygen　on　catalysts　surface.