PROBLEM TO BE SOLVED: To provide a hyaluronic acid synthesis promoter and a skin care preparation having higher effects by using a material being natural and having high safety.SOLUTION: Pomegranate juice or its lactobacillus fermentation product has an excellent hyaluronic acid synthesis promoting effect, particularly, the lactobacillus fermentation product is preferable, and, as the lactobacillus to be used, Lactobacillus plantarum is preferable. This hyaluronic acid synthesis promoter increases the synthesis ability of hyaluronic acid in vivo, thus can be used for the prevention and/or treatment of the aging of a skin, skin diseases such as atopic dermatitis, psoriasis, ichthyosis and arthritis such as rheumatisms, and can be blended into medicine, quasi drugs, cosmetics, foods or the like.
