Not only does this paper examine the etymology of yuan元, yuan原, yuan源 and ben本 through Sinoxenic vocabulary but conducts comparative analyses of similarities and differences in them as well. yuan元 means ‘beginning, first’ and ‘root, origin’ in Sinoxenic words. However, its role was replaced with yuan原 at the beginning of the Ming Dynasty. yuan原was originally used to mean ‘first, beginning’ and ‘origin, source’, the former of which has strengthened and the latter of which has become transferred to yuan源to which more meanings of ‘root, by nature’ have been added since then. ben本 means ‘nature, essence, basis’ referring to the essence or nature itself, thereby differentiated both from yuan源, whose meaning indicates the origin of such essence or nature, and from yuan原, which means ‘first’ and ‘beginning (initial appearance or status)’.