We explored effects of the degree of supersaturation, which depends on solution concentration, pH, and temperature, on the development of microstructures of the TiO(2) thin films deposited from the controlled hydrolysis of TiCl(4) aqueous solutions. It was shown that, with precursor (TiCl(4)) solution of low degree of supersaturation, a porous flower-like dendritic structure was synthesized, while a densely packed particulate nanostructure was obtained with that of high degree of supersaturation. The former morphology was attributed to the directional growth of TiO(2) crystals from the already-deposited films, whereas the latter to the bulk precipitated TiO(2) nanoparticles nucleated in the solution, followed by their attachment and self organization. By establishing the processing-microstructure relations, this study provided a means of generating a wide spectrum of reproducible TiO(2) microstructures using the low-temperature aqueous solution processing.