An allyl group was introduced to SBA-15 by the reaction of allylmagnesium bromide with chlorinated SBA-15 obtained by the treatment of calcined SBA-15 with thionyl chloride. The allyl group was converted to a mercaptopropyl group by photochemical reaction with liquid hydrogen sulfide, and then the sulfopropyl group-functionalized SBA-15 was obtained by acidification. The sulfopropyl group in the resulting material was anchored to the SBA-15 surface by a Si-C covalent bond and showed high thermal stability in comparison with that introduced by the conventional silane-coupling method.