Macroporous TiO2 films have been prepared by sol-gel method without any surfactant and colloidal templates. The gel TiO2 films deposited from the precursor solutions containing photo monomer were irradiated by the UV light for some time. The UV irradiation could induce the monomer to polymerize, which resulted in two phases in the films, one was the emerging polymer rich phase, and another was the residual monomer-TiO2 oligomer rich phase. After heat-treatment, a well-defined interconnected macroporous TiO2 films could be obtained. SEM and AFM results showed that the macroporous structures of the films could be tuned by changing the reaction parameters. The as-prepared macroporous TiO2 films exhibited much higher photocatalytic activity for the photodecomposition of methylene blue dye than that of the dense film.