TiO2-nanoparticles of anatase-type were synthesized and deposited using the electrophoresis depo-sition method. All of TiO2-nanoparticles were positively charged in colloidal aqueous solution and were attracted toward ITO glass as the negative electrode as same as nanoparticles (P25) whose diameter is larger than that of TiO2-nanoparticles. Many of the TiO2-nanoparticles were connected with each other and formed clusters, although single TiO2-nanoparticles were also observed. The cracks generated in the thin film with increasing the deposition time and thin film was flaked off from substrate. High optical transparency TiO2-nanoparticles-thin film without cracks was deposited when the deposition time was short. Moreover, the thickness of TiO2-thin film, which has high optical transparency and no cracks, could be increased using mixture of TiO2-nanoparticles and P25.