The　Pd/Al2O3　catalyst　promoted　with　La2O3　for　anthraquinone　hydrogenation　to　H2O2　was　prepared　by　impregnating　Al2O3　with　aqueous　solutions　of　lanthanum　nitrate　and　Na2PdCl4　succesively.　The　effect　of　lanthanum　oxide　on　the　catalytic　performance　of　Pd/Al2O3　catalyst　was　investigated　by　means　of　X-ray　diffraction,　N-2　adsorption,　temperature-　programmed　desorption　of　CO2,　H-2-O-2　titration　and　electron　probe　microanalysis.　The　results　showed　that　lanthanum　oxide　was　a　good　promoter　of　Pd/Al2O3　for　the　reaction.　It　could　inhibit　the　growth　of　alumina　crystals　at　high　temperature,　increase　the　surface　area,　enhance　the　surface　alkalinity　of　Al2O3,　improve　the　Pd　dispersion　on　the　support,　increase　the　Pd　concentration,　decrease　the　Pd　layer　thickness　on　the　catalyst　surface,　and　thus　improve　the　catalytic　activity　effectively.　The　addition　of　La2O3　could　decrease　the　Pd　loading　from　0.　281　%　to　0.　188　%,　while　the　catalyst　activity　increased　by　44　%