Disclosed is an oily dispersion of an inorganic microparticle oxide powder that exhibits excellent texture, and has superior compatibility with other cosmetic material components, since it uses highly stable hydrocarbon-based oils such as ester oils or liquid paraffins, and has a high solid concentration, a low viscosity and superior stability over time, and a cosmetic material having high SPF value or transparency using the oily dispersion. The oily dispersion contains only two components of a dispersion medium and a surface-treated inorganic microparticle oxide powder, wherein the dispersion medium is an oil, the surface-treated inorganic microparticle oxide powder is a powder surface-treated with branched fatty acid containing isostearic acid as a primary constituent component or a metal salt containing isostearic acid as a primary constituent component at an amount of 1 to 30% by weight with respect to the powder as a base material, and the surface-treated inorganic microparticle oxide powder has a solid concentration of 25% by weight or more and a viscosity of 2,000 mPa·s or less at 25°C in the preparation of the oily dispersion.
