The present invention is directed to providing substance used as a crystallization accelerator for fat composition and fat compositions using thereof. The fat composition is provided with good crystallization-accelerating performance and used for improving sugar droplet, sticky residue and oral taste of fried doughnut, filling status and hardness of shortening/margarine, drying time, workability, processing capability and oral taste of chocolate coatings. The constituent of the crystallization accelerator of the present invention includes hydroxyl saturated fatty acid of 18 to 28 carbon atoms having a carboxyl group and a hydroxyl group at ends and one optional carbonyl group in the chain, glycerine and suitable fatty acid. The constituent is polymerized with ester bonds into polymer compound having 3,000 to 100,000 molecular weights.本發明之課題係提供使油脂具有優良結晶促進效果之物質、及調合結晶促進劑之油脂組成物。油脂組成物以其優良之結晶促進作用改善油炸甜甜圈之砂糖熔滴、黏殘渣、食用感覺，酥油/人造奶油之充填狀態、硬度，及巧克力包衣之乾燥時間、作業性及加工性，並改善食用感覺。本發明之構成成份為包含：於兩端具有羥基及羧基，鏈中含有一個選擇性的羰基，碳數為18~28之羥基飽和脂肪酸、甘油及適量脂肪酸，而前述構成成份為由酯鍵所聚合之分子量為3,000~100,000之高分子化合物的結晶促進劑。
