The present invention provides a simple and efficient technique for obtaining a composition containing solid fats and oils without solidifying the liquid fats and oils mixture of the liquid fats and solidifying them. The present invention hardens a liquid fat and oil mixture containing solid fat and liquid oil in the presence of a fat and oil hardener containing cellulose.本發明提供一種不使固體脂與液狀油之液狀油脂混合物分離而進行固形化,獲得含固狀油脂之組合物的簡便且高效之技術。本發明於包含纖維素之油脂硬化劑之存在下,使包含固體脂及液狀油之液狀油脂混合物硬化。