Mesoporous　thiol-functionalized　SBA-15　silicas　have　been　directly　synthesized　by　co-condensation　of　tetraethyl　orthosilicate　and　3-mercaptopropyltrimethoxysilane　with　triblock　copolymer　poly(ethylene　glycol)-B-poly(propylene　glycol)-B-Poly(ethylene　glycol)　as　structure-directing　agent　under　hydrothermal　condition.　Mesoporous　structure　was　obtained　after　the　surfactant　removal　by　Soxhlet　ethanol　extraction.　These　materials　have　been　characterized　by　means　of　powder　X-ray　diffraction,　nitrogen　sorption,　transmission　electron　microscopy,　thermogravimetry　analysis,　elemental　analysis　and　solid　state　Si-29　nuclear　magnetic　resonance.　The　effect　of　3-mercaptopropyltrimethoxysilane　concentration　in　the　initial　mixture　on　the　pore　structure　of　functionalized　SBA-15,　including　pore　ordering,　surface　area,　pore　size　and　pore　volume,　is　investigated　in　detail.　In　order　to　functionalize　the　SBA-15　silicas　without　a　significant　change　of　pore　structure,　the　molar　concentration　of　3-mercaptopropyltrimethoxysilane　should　be　limited　to　less　than　20%.　(C)　2005　Elsevier　B.V.　All　rights　reserved.