TiO₂ nanotubes-assembled hierarchical microspheres were fabricated by a one step hydrothermal route using P25 in NaOH aqueous solution with the assistance of H₂O₂, followed by temperature-programmed calcinations treatment at 400 °C. The photocatalytic activity of the sample was investigated by degradation of methyl orange under UV-light irradiation. The results show that TiO₂ nanotubes-assembled hierarchical microspheres exhibit much higher photocatalytic degradation activity compared with that of TiO₂ nanotubes, which could be attributed to its larger surface area, greater light reflection and the good light multiple scattering property.