The present invention relates to a powder modifying agent containing Nε-octanoyl-L-lysine, a composite powder modified using same, and a makeup cosmetic containing the composite powder.According to the present invention, a powder modifying agent that can impart a powder for cosmetics with the properties appropriate as a powder for makeup cosmetics, namely, superior dispersibility and superior caking property when blended with makeup cosmetics, superior texture (e.g., smoothness, moist feeling etc.) when applied to the skin, and water-repellency, adhesiveness and transparency, can be provided, and further, a composite powder capable of exhibiting the above-mentioned properties in good balance, and a makeup cosmetic superior in sense of use, water-repellency, adhesiveness and transparency can be provided.