Organic-inorganic composite particles includes inorganic oxide particles each of which has a cationic charge on the particle surface and polymer gel molecules which are derived from a natural substance, have an anionic functional group and one or more hydroxyl groups in a molecule and have both a shrinking and a swelling property, the polymer gel molecules are electrostatically bonded to surfaces of the inorganic oxide particles; a process for producing the particles; a dispersion containing the particles; and a cosmetic containing the particles. These organic-inorganic composite particles have good dispersibility not only in aqueous solvents such as water but also in non-aqueous solvents and further have characteristics that aggregation of the particles scarcely occurs.