Porous TiO2 microspheres were prepared in air atmosphere using sol-gel-adding electrolyte method, which is simple and reproducible. The TEM image shows that the diameter of microspheres is around 550 nm. BET measurement indicates that TiO2 microspheres are of high specific surface area and have a uniform pore size distribution with a mean pore size of 4.4 nm. The pores of the TiO2 microspheres are monodispersive, mesoporous and interconnecting. XRD shows that calcination at 500 degrees C transformed the TiO2 microspheres from amorphous to anatase phase. The degradation experiment demonstrates that the photocatalytic, activity of TiO2 microspheres toward methylene blue dye photodegradation is more efficient than that of the commercial TiO2 powder. Moreover, the microspheres can be easily removed from the treated solution. (C) 2007 Elsevier Ltd. All rights reserved.