Ordered mesoporous silica of SBA -15 type was modified with 3-(trihydroxysilyl)-1-propanesulfonic acid (TPS) in order to obtain a solid acid catalyst. The structure and surface properties of the materials obtained were com- pared with those of SBA -15 silica modified with (3-mercaptopropyl)trimethoxysilane (MPTMS). For this purpose the samples were examined by low temperature N 2 adsorption/desorption, XRD, TEM, FTIR, XPS and elemental analysis. Successful incorporation of TPS species on the silica surface was proved. The catalytic activity of the materials obtained was investigated in acetic acid esterification with n-butanol and n-hexanol. Despite a lower concentration of acidic sites, TPS-modified materials showed a superior catalytic behavior over MPTMS modified sample. Moreover, the TPS containing catalysts showed a stable catalytic activity after drying and application in subsequent process.