Ordered　mesoporous　silicon-doped　gamma-alumina　with　high　thermal　stability　was　synthesized　by　a　modified　sol-gel　process　with　the　assistance　of　carboxylic　acid　as　interfacial　protector　in　the　presence　of　aluminum　isopropoxide,　tetraethylorthosilicate　and　Pluronic　P123.　The　effect　of　molecular　structure,　complexation　ability　and　volatility　of　carboxylic　acids　on　the　thermal　stability　of　the　obtained　alumina　was　investigated.　Structural　and　morphological　characterization　indicated　that　the　silicon-doped　gamma-alumina　assisted　with　acetic　acid　possesses　long-range　ordered　20　hexagonal　mesostructure　even　after　the　calcined　temperature　up　to　1000　degrees　C　and　confirmed　the　retention　of　the　mesoporous　structure　with　a　large　surface　area　of　243.50　m(2)　g(-1),　pore　volume　of　0.6　cm(3)　g(-1)　and　narrow　pore　size　distribution,　demonstrating　the　highly　thermal　stability　of　the　resulting　alumina.　(C)　2015　Elsevier　B.V.　All　rights　reserved.