Based on the external characters, genital structures, distribution, and intermediate individuals from contact zones, the endemic species Amathuxidia morishitai Chou & Gu, 1994 from Hainan, China is treated as conspecific with A. amythaon (Doubleday, 1847) and is downranked to a subspecies of the latter, i.e., Amathuxidia amythaon morishitai stat. nov. Meanwhile, two subspecies groups of A. amythaon are recognized by morphological and genetic evidence, termed amythaon-group (A. a. amythaon + A. a. dilucida (Honrath, 1884)) and annamensis-group (A. a. morishitai + A. a. annamensis Talbot, 1932) with the latter group showing a deeper divergence than normal on a subspecific level genetically.