The present invention provides a modified powder that is obtainable by coating the surface of a base powder with a hydrophobizing agent and a cationic surfactant. In the modified powder described above, it is preferable that the amount of coated hydrophobizing agent and the amount of coated cationic surfactant are 3 to 90% by mass and 0.5 to 10% by mass, respectively, relative to the self weight of the base powder. In the modified powder described above, it is preferable that the mass ratio of the coated hydrophobizing agent and the coated cationic surfactant is from 1:1 to 9:1. In addition, the present invention provides a cosmetic composition comprising the above modified powder wherein the modified powder and the base powder have an ultraviolet scattering effect. In the cosmetic composition described above, it is preferable that the blended amount of the modified powder is from 0.5 to 100% by mass. Furthermore, the present invention provides a sunscreen cosmetic composition comprising the above modified powder with an ultraviolet scattering effect. In the sunscreen cosmetic composition described above, it is preferable that the base powder is one or more selected from the group consisting of titanium oxide, zinc oxide, iron oxide, cerium oxide, bismuth oxide, zirconium oxide, chromium oxide, and tungstic acid. In the sunscreen cosmetic composition described above, it is preferable that the blended amount of the modified powder is from 1 to 40% by mass.