The invention provides a process for powdering highly unsaturated fatty acid esters of ascorbic acid which are pasty and problematic in physical properties by a simple and easy means; highly unsaturated fatty acid esters of ascorbic acid which are improved in stability by powdering; and compositions containing the powdered highly unsaturated fatty acid esters of ascorbic acid. Specifically, a process for powdering a highly unsaturated fatty acid ester of ascorbic acid as represented by the general formula (I): RCO-A [wherein RCO— is acyl derived from a highly unsaturated fatty acid; and A is an ascorbic acid residue bonded through an —O— linkage resulting from an hydroxyl group of ascorbic acid], characterized by mixing a highly unsaturated fatty acid ester of ascorbic acid as represented by the general formula (I) with an aqueous solution of a water-soluble filler to form an emulsion and dehydrating and drying the emulsion by a spray drying method.