A　series　of　C/SiC　composites　was　successfully　synthesized　via　the　carbothermal　reduction　of　carbonaceous　silicon　xerogel,　which　was　prepared　from　the　sol　gel　method　by　using　tetraethoxysilane　TEOS　and　saccharose　as　the　raw　materials.　The　obtained　samples　were　characterized　by　X-ray　powder　diffraction　XRD　and　N-2　physical　adsorption.　The　specific　surface　areas　of　the　as　prepared　C/SiC　composites　varied　from　329　to　849　m(2)/g.　The　average　pore　diameters　and　the　total　pore　volumes　were　in　the　range　of　4.5-7.6　nm　and　0.53-1.12　cm(3)/g,　respectively.　The　as　prepared　C/SiC　composites　were　proved　to　be　effective　supports　for　Ru　catalysts　for　ammonia　synthesis　At　435　degrees　C,　10.0　MPa　and　a　N-2/H-2　(1/3)　flow　rate　of　10000　h(-1),　the　optimum　activity　of　15.9%　ammonia　in　the　effluent　was　reached　when　C/SiC-5　(C/TEOS)　molar　ratio　=　5)　was　used　as　the　catalyst　support.　(C)　Elsevier　B.V.　All　rights　reserved.