A species delimitation problem was found in three Asian species of Merremia Dennst. ex Endl. section Xanthips Hallier f., namely M. bambusetorum Kerr, M. kingii (Prain) Kerr and M. umbellata (L.) Hallier f. Therefore, this work aims to examine the morphological, micromorphological and anatomical characters that might help clarify species delimitation in this species complex. The results revealed that length of sepals, type of sepals in the same flower, type of bracts and inflorescences are morphologically diagnostic characters. The diagnostic micromorphological characters are the presence of trichomes on the stem, leaves and filaments, and the anticlinal wall of leaf epidermal cells raised into ridges. The anatomical characters that are useful to delimit these species are the shape of the stem and petiolar ridges in cross section, and the difference in size of epidermal cells between adaxial and abaxial leaf epidermis. These diagnostic characters are useful to delimit and clarify all species.