Provided is an aqueous dispersion comprising dispersed particles containing lecithin and a pentacyclic triterpene having at least one substitution group selected from the group consisting of carboxyl groups and groups derived from carboxyl groups, wherein the amount of phospholipid in the lecithin is, by mass standard, within a range of twice to ten-times the amount of the pentacyclic triterpene and the volume-average particle diameter of the dispersed particles is 10nm to 70nm.