To provide a vesicle-containing composition wherein the stability is improved and the rate of releasing drug or perfume is sufficiently restricted during administration in vivo or application to the skin surface. Silica polymerization on the outer surfaces of vesicles is facilitated by adding a specifically structured water-soluble silane derivative to an aqueous composition containing the vesicles composed of a surfactant and mixing them together, and vesicle-silica composites having silica-coated outer surfaces can be obtained, resulting in the improved stability of the vesicle-containing composition as well as the improved effect of restricting the rate of releasing drug or perfume during administration in vivo or application to the skin surface.