Abstract: In order to make use of the superior photocatalytic activity of TiO₂ and the structural properties of montmorillonite (MMT), TiO₂/MMT composites were fabricated by hydrolysis precipitation method using MMT as carrier, TiCl₄ as raw material and ammonium hydroxide as precipitant firstly. Then, the component, crystal form, structure and morphology were characterized by FTIR, XRD and SEM. Finally, under the irradiation of ultraviolet light, the photocatalysis degradation activity of TiO₂/MMT composites with different TiO₂ contents for simulation phenol waste water were investigated, and the tracking experiments were conducted for the process of phenol photocatalysis degradation by composites combined with ultraviolet-visible spectra. The results illustrate that TiO₂ in the prepared TiO₂/MMT composites is anatase phase, and the crystallite dimension on MMT is 7.8 nm. The domain components of interlayer in TiO₂/MMT composites are replaced by titanium pillars, and the pillared reaction processes in the interlayer regions. Thus the basic frame of MMT does not change, and TiO₂ spreads on the surfaces of MMT. When the initial concentration of phenol is 10 mg/L, the pH of phenol solution is 6 and the ultraviolet irradiation time is 150 min, the degradation rate of 37.5wt% TiO₂/MMT composites for phenol is 63%, superior than that of MMT (4.5%) and pure TiO₂ (55%), displays that the loading of MMT improves the photocatalytic activity of TiO₂.