PROBLEM TO BE SOLVED: To provide a cosmetic raw material which has good compatibility with other cosmetic raw materials, especially an ultraviolet absorber having poor solubility, and therefore can improve compounding stability of a cosmetic and which can provide the cosmetic with good water resistance, sebum resistance, gloss, tactile, adhesion to hair and skin, and the like； and to provide a cosmetic obtained by compounding the cosmetic raw material, which has excellent surface protective characteristics, appearance and use feeling.SOLUTION: Provided is a copolymer in which 45 to 60 mass% of all monomer units is an unsaturated monomer having a specific carbosiloxane dendrimer structure. Also provided are a composition, a cosmetic raw material, and a cosmetic each containing the copolymer.【課題】他の化粧料原料、特に難溶性の紫外線吸収剤との相溶性がよく、したがって、化粧料の配合安定性を向上することができ、また、化粧料に良好な耐水性、耐皮脂性、光沢、触感、毛髪・皮膚への付着性等を付与し得る化粧料原料、並びに、該化粧料原料を配合してなる優れた表面保護特性、外観及び使用感を備えた化粧料を提供する。【解決手段】全モノマー単位中の４５質量%～６０質量％が特定のカルボシロキサンデンドリマー構造を有する不飽和単量体である共重合体、当該共重合体を含む組成物、化粧料原料および化粧料。【選択図】なし
