,Magnetic TiO2/montmorillonite (MMT) /Fe3O4 nanocomposites were prepared by a single step of hydrolysis. First, a tetra-n-butyl titanate microemulsion wrapping Fe3O4 nanoparticles (NPs) was established through ultrasonic process. Then, the microemulsion was intercalated into MMT layers by vigorous stirring. Thereafter, in a controllable hydrolysis process, the TiO2 NPs were embedded into the layers of MMT. The adsorption and photocatalytic activity were evaluated by using the methylene blue (MB) as contaminants. The results indicated that anatase-TiO(2)NPs (10-20 nm in diameter) were embedded in the layers of MMT and Fe3O4 NPs (45-60 nm in diameter) were deposited on the surface of MMT. Additionally, ca. 94% of the initial MB was decomposed by TiO2/MMT/Fe3O4 nanocomposite after 80 min UV irradiation, while ca. 85% of the initial MB was decomposed by TiO2 NPs. Furthermore, after being used 6 times, the TiO2/MMT/Fe3O4 nanocomposite still maintained a high degradation rate and revealed good reuseability.