Disclosed herein are an extract emulsified oil comprising an antioxidant, in which lecithin and an edible oil are mixed with a molasses extract, an extract of raw sugar-ion resin reclaimed water or an olive leaf extract, a cooking oil containing the same, and a preparation method therefor. According to the present invention, an emulsified oil capable of extending a replacement cycle of a cooking oil by controlling the coloration of the cooking oil upon heating and maintaining a quality of fried food, that is, capable of having excellent thermal stability of undesirable color, and a cooking oil containing the same may be prepared.