Employing　phthalic　acid　(PA)　as　an　interfacial　protector　and　P123　as　a　structure-directing　agent,　ordered　mesoporous　gamma-alumina　with　2D　hexagonal　symmetry　was　successfully　synthesized　through　the　sol-gel　method.　According　to　the　results,　the　best　molar　ratio　of　PA/Al3+　to　synthesize　the　ordered　alumina　is　0.25　and　the　phthalic　acid　serves　as　an　interfacial　protector　to　protect　the　aluminum　ions　at　the　organic-inorganic　interface　from　being　affected　by　chloride　ions　during　the　whole　evaporation　process.　The　resulting　alumina　possesses　a　surface　area　of　431.98　m(2)/g　and　a　pore　volume　of　0.42　cm(3)/g.　After　the　alumina　converted　into　the　gamma-alumina　phase,　the　surface　area　is　still　226.37　m(2)/g　and　has　a　pore　volume　of　0.31　cm(3)/g.　(C)　2010　Elsevier　B.V.　All　rights　reserved.