Hydrophobic　organic-inorganic　hybrid　silica　sols　were　prepared　using　1,2-bis(triethoxysilyl)　ethane　(BTESE)　and　1H,　1H,　2H,　2H-perfluorodecyltriethoxysilane(PFDTES)　as　precursors　under　acidic　condition,　then　the　sols　were　deposited　on　gamma-Al2O3/alpha-Al2O3　substrates　by　dip-coating　under　clean　room　condition.　The　cross-sectional　morphology,　particle　size　of　the　sols　and　hydrophobic　property　of　the　membranes　were　characterized　by　means　of　SEM,　DLS,　FTIR,　water　contact　angle　measurement　and　thermogravimetric　analysis.　The　results　show　that　the　particle　size　of　sols　and　the　water　contact　angle　of　supported　membranes　increase　with　increasing　the　amount　of　PFDTES　in　the　mixture.　A　narrow　sol　particle　size　distribution　centered　at　3.69　nm　and　a　water　contact　angle　of　(112.0　+/-　0.4)degrees　were　obtained　at　a　BTESE/PFDTES　molar　ratio　of　0.25　:　1.　At　300　degrees　C,　the　membrane　shows　a　high　H-2　permeance　of　5.99x10(-7)　mol　.　m(-2)　.　Pa-1　.　s(-1)　and　a　H-2/CO　and　H-2/CO2　permselectivity　of　9.54　and　5.20,　respectively,　which　were　higher　than　the　corresponding　Knudsen　value　(H-2/CO=3.74,　H-2/CO2　=　4.69).　The　H-2　transport　in　the　modified　silica　membranes　is　subjected　to　a　micropore　diffusion　mechanism.