New mesoporous silicotinphosphate materials with different Si:Sn:P mole ratios have been synthesized under hydrothermal condition using the self-assembly of cationic surfactant under mild acid pHs and characterized by elemental analysis, XRD, TEM, SEM-EDS, N-2, sorption, FF IR, and UV-vis diffuse reflectance measurements and ion-exchange studies. XRD and TEM results suggested a wormhole-like disordered framework in this material. N-2 adsorption studies revealed that the pore diameters of different samples were 1.7-2.2 nm. FIF IR and UV-vis spectroscopic studies suggested the presence of Sn-O-P, Sn-O-Si bonds and tetrahedral coordination of Sn(IV) in these novel mesoporous materials. These novel silicotinphosphate materials showed good anion-exchange capacities (2.56-0.27 mmol g(-1), which correspond well with their respective Si:Sn:P mole ratios in the solid products) and catalytic activity in the liquid phase epoxidation of styrene using dilute H2O2, as oxidant. (c) 2005 Elsevier B.V. All rights reserved.