Abstract: Mesoporous MTS-1 was prepared by organic alkali modification of hydrothermally synthesized TS-1 molecular sieve substrate. The orphological and interfacial properties were systematically characterized by XRD, N₂ sorption isotherm, UV-vis spectroscopy and TEM techniques. The results show that the modification can apparently improve the specific surface area and pore volume. Under irradiation of ultraviolet light, RhB was used as probe molecule for investigation on photocatalytic activity of MTS-1. The photocatalytic kinetics of TS-1 and MTS-1 both follow the pseudofirstorder kinetics. The two catalysts show similar catalytic activity at the initial stage, whereas MTS-1 exhibits apparently higher photocatalytic activity over TS-1 with the prolonging of reaction duration.