TiO₂ hydrate coating on mica in an aqueous solution of TiOSO₄ by the hydrolysis using ammonia water studied with emphasis on coating conditions for a uniform coating. For the uniform coating of TiO₂ film on mica surface, it was found that smaller mica particles were coated more uniformly compared to lager particles. It was necessary to suppress the rate of formation of hydrated TiO₂ particles in solution, which were deposited on mica and generate irregular coating. It was also necessary to control precipitation yield by varying the reaction temperature to obtain uniform coating. More uniform coating was obtained with higher precipitation yield. A uniform dense film was formed when mica particles of average size of 14.7㎛ is used for mica slurry solution, of which pH is 2.5, and the factor of acidity of TiOSO₄ solution is 291, and the solution was kept at 80℃ for 3 hours. The morphology of TiO₂ film formed on mica was little affected by firing at 900℃.