Provided is a lubricity improver capable of improving lubricity and storage stability due to anti-oxidation, the lubricity improver containing a saturated fatty acid methyl ester derivative including at least one 1,2-dimethoxy ethylene structural unit represented by Chemical Formula a below, obtained by converting a double bond (olefin) of biodiesel, which is used as a lubricity improver of fuel, that is, the existing fatty acid methyl ester (FAME), into a dimethoxy group.