PURPOSE: To stabilize a highly unsaturated fatty acid and to obtain an O/W/ O-type emulsified oil and fat composition useful as a drug or nutrient food, etc., for the prevention of adult diseases, by adding a highly unsaturated fatty acid to inner oil phase.

CONSTITUTION: In the conventional production of an O/W/O-type emulsified oil and fat composition, about ≥1%, preferably about ≥2% highly unsaturated fatty acid such as linoleic acid, oleic acid, arachidonic acid, etc., or their derivative such as triglyceride, diglyceride, monoglyceride or ethyl ester, etc., and, if necessary, about 0.01W0.1%, preferably about 0.05W0.1% antioxidant such as tocopherol, butylhydroxyanisole, etc., are added to the inner oil phase.