There are three different views on the identification of the sitter in the Louvre version of Mona Lisa and the meaning of the work.The sitter are interpreted as the wife of a silk merchant at that time;as the"ideal woman"corresponding to the description of the"Dolce stil nuovo";or the image of the Virgin Mary.There are also different interpretations of the dress,as the contemprary fashion;as an imaginary ideal dress;or stylized costume for religious figures.The paper points out the reasons and existing problems in the three interpretations,and the problems in the study of dress of other artworks.