High　thermally　stable　mesoporous　alumina　doped　with　lanthanum　was　synthesized　using　inorganic　nitrates　as　precursors　and　employing　pluronic　P123　(P123,　(EO20PO70EO20,　EO=ethylene　oxide,　PO=propylene　oxide))　as　a　structure-directing　agent.　After　calcination　at　400　degrees　C,　the　resultant　lanthanum　doped　alumina　exhibited　a　gamma-Al2O3　phase,　which　was　the　same　as　pure　alumina.　After　the　thermal　treatment　up　to　1200　degrees　C,　La-doped　Al2O3　generated　only　one　phase　of　theta-Al2O3　rather　than　two　mixed　phase　of　theta-Al2O3　and　alpha-Al2O3　and　the　surface　area　could　still　maintain　101　m(2)/g　with　a　keeping　pore　volume　of　0.66　cm(3)/g.　The　excellent　thermal　stability　was　explained　by　the　titration　of　strong　Lewis　acid　sites　of　gamma-Al2O3　with　the　assistance　of　highly　dispersed　lanthanum　species　covering　on　alumina.　Furthermore,　the　lanthanum　modified　mesoporous　alumina　was　preliminarily　employed　as　a　stable　support　for　Pd　in　the　catalytic　oxidation　of　C3H8.