In this work, highly-ordered TiO2 nanotubes arrays were fabricated by two-step anodic oxidation method to serve as photoanodes for dye-sensitized solar cells. We investigated the effect of TiCl4 treatment on the microstructure and morphologies of TiO2 nanotubes arrays. It is found that the TiCl4 treatment can generally introduce 10-15 nm TiO2 nanoparticles into the TiO2 nanotube arrays. The photovoltaic performance of dye-sensitized solar cells is related to the concentration and treated-time of TiCl4 treatment. A power conversion efficiency of 7.63% was achieved for dye-sensitized solar cell with photoanode treated by 0.04 M TiCl4 for 60min. The improved power conversion efficiency can be attributed to the increased available surface for dye adsorption in photoanodes.