Monodisperse colloidal TiO2 microspheres with different size have been synthesized via controlled hydrolysis of tetrabutyltitanate (TBOT) in ethanol with addition of a salt solution. The photoelectric conversion performances of dye-sensitized solar cells (DSSCs) based on TiO2 microspheres were investigated. The results revealed that these TiO2 microspheres, which were well dispersed and uniform, and their size became gradually smaller with the increasing KCl concentration. The DSSC based on smaller TiO2 microspheres exhibited an enhanced photocurrent and conversion efficiency, which was attributed to its better absorption properties of dye molecules and superior conductivity. After the further optimization, the total conversion efficiency of DSSC with electrode 2 was 5.72%. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.