Novel Fe doped mesoporous TiO 2 microspheres were fabricated by an ultrasonic–hydrothermal method when tetrabutyl titanate was used as a precursor and octadecylamine was used as a structure-directing agent. The mesoporous materials were characterized by XRD, SEM, TEM, N 2 adsorption–desorption measurements, XPS, FL, and UV–vis. The results suggest that both ultrasonic treatment and hydrothermal procedure are critical for the fabrication of Fe doped mesoporous TiO 2 microspheres with a combination of regular morphology, large specific surface area, high crystallinity, and high thermal stability. Low-angle XRD and TEM images indicate that the disordered wormhole-like mesostructure of Fe doped TiO 2 microspheres with diameters of about 300−400nm is actually formed by the agglomerization of nanoparticles with an average size of about 10nm. The photocatalytic activity of Fe doped mesoporous TiO 2 microspheres was evaluated by the photodegradation of methyl orange. A small amount of Fe 3+ can obviously enhance their photocatalytic activity. The optimal atomic ratio of Fe to Ti for photocatalytic activity is about 0.5at%.