The present invention provides a raw material for cosmetics and an oil-in-water emulsified cosmetic using core-corona type polymer particles excellent in emulsion stability and feeling in use.The raw material for cosmetics of the present invention is composed of core-corona type polymer particles which are obtained by radical polymerization of a polyethylene oxide macromonomer represented by the general formula (1) with one or two or more kinds of hydrophobic monomers represented by the general formulas (2) to (3) under the conditions of (A) to (D).本發明提供一種使用乳化安定性及使用感優異之芯-冕型聚合物粒子之化妝料用原料及水中油型乳化化妝料。本發明之化妝料用原料係由通式(1)表示之聚環氧乙烷巨分子單體與通式(2)至(3)表示之疏水性單體的1種或2種以上於(A)至(D)的條件下進行自由基聚合而得到之芯-冕型聚合物粒子所構成者。
