Two types of the polyimide-polysilsesquioxane hybrid composite were prepared via sol-gel process. The one used the organo-soluble polyimide that had hydroxy groups in the polymer main chain as the matrix polymer. The other case used the silyl-functionalized polyimide as the matrix polymer for the sol-gel process. The one hybrid composite showed the higher glass transition temperatures than the organo-soluble polyimides. The formed silica domain size was ca. 100-250 nm, regardless of the type of silica precursor. The refractive indices`` range of these composites was 1.529-1.563. The dielectric constant ranged from 2.88 to 3.16. The other composites showed no glass transition temperature. The domain size of the silica was below 100 nm. The surface roughness increased as the content of the fluorine increased. The refractive indices had the range from 1.610 to 1.640. The dielectric constants ranged from 3.28 to 3.60.