A method of purifying episesamin capable of obtaining an episesamin-rich composition having a high content of episesamin by bringing a mixture of sesamins containing sesamin, episesamin and the like into contact with an aqueous medium thereby to obtain a slurry mixture and then separating a solid matter from the resulting mixture or dissolving the mixture of sesamins by heating in an appropriate aqueous medium and carrying out recrystallization by gradually cooling the resulting solution is disclosed. According to the invention, episesamin can be simply and efficiently purified from a mixtureof sesamins containing mainly sesamin and episesamin.