The present invention provides a core-corona type polymer particle which is excellent in emulsion stability and feeling in use, a raw material for cosmetic using the particle, and an oil-in-water emulsion cosmetic.The core-corona type polymer particle of the present invention is obtained by radical polymerizing a polyethylene oxide macromonomer represented by general formula (1) and one or two or more hydrophobic monomers represented by the general formulas (2) to (3) under the following conditions (A) to (D).本發明提供一種乳化安定性及使用感優異之芯-冕型聚合物粒子、使用該粒子的化妝料用原料及水中油型乳化化妝料。本發明之芯-冕型聚合物粒子係由通式(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種以上在下述(A)至(D)的條件下進行自由基聚合而得者。
