Thick inorganic-organic hybrid films were prepared on ITO-coated glass substrates by the electrophoretic sol-gel deposition of polyphenylsilsesquioxane particles. The morphology of the deposited films changed from the aggregate of the spherical particles to monolith by heat treatment at temperatures higher than $200^{circ}C$. Transparency of the films was significantly improved accompanied by the morphological change of the particles. The degree of the morphological change was governed by two factors; maximum heat treatment temperature and heating rate. Transparent thick films of ca. 3$mu extrm{m}$ in thickness were obtained only by heat treatment at $400^{circ}C$ for 2h with rapid heating from room temperature to $400^{circ}C$. These films obtained were strongly adhered to the ITO-coated glass substrates and has a very smooth surface.