To provide an oil containing a polyunsaturated fatty acid that has a lower content of saturated fatty acid. MEANS TO SOLVE THE PROBLEM A method for lowering saturated fatty acid content, the method comprising the step of concentrating polyunsaturated fatty acid using a lipase having low reactivity for the polyunsaturated fatty acid to react with a glyceride containing a polyunsaturated fatty acid wherein the lipase reaction is performed at a temperature of not more than 25°C. The lipase is preferably a lipase derived from a microorganism belonging to the genus Candida, Alcaligenes, Burkholderia, Pseudomonas, Thermomyces, or Rhizomucor. Also, with this method, a glyceride having docosahexaenoic acid content of not less than 40 area percent and a saturated fatty acid content of not more than 12 area percent can be obtained.
