As an inorganic sunscreen material, nano-titanium dioxide (nano-TiO 2 ) owns broad prospects in sunscreen cosmetics for its small size, non-toxicity, strong covering ability, UV absorption and scattering abilities, etc. Nano-TiO 2 has high photocatalytic activity, so it will go through a series of complex chemical reactions under light irradiation and cause damage to its surrounding agents. In addition, it is hard to disperse in various aqueous and non-aqueous mediums due to its high surface energy and hydrophobic property. In order to apply nano-TiO 2 to cosmetics effectively and safely, its surface modification is necessary. This paper reviews nano-TiO 2 's preparation, modification, and its application in sunscreen cosmetics.