Abstract:Micromorphological characters of leaf abaxial epidermis of 20 species, 6 subspecies and 2 varieties of Poa was examined by light microscope and scanning electron microscope, to infer its significance for classification of the genus Poa.The results indicated that: (1) the leaf abaxial epidermis of Poa were characterized by longtubular, fusiform or shorttubular longcells with straight or sinuous wall; presence or absence of shortcells in intercostal zone; frequent stomata and parallelsided or domeshaped subsidiary cells distributed in intercostal zone; presence or absence of pricklecells in costal zone, absence of pricklecells in intercostal zone; elliptic, reniform, crescentic, subsquare, horizontallyelongated sinuous or nodular silicacells distributed solitary or in pairs in costal zone; presence of crown cells in some species. (2) Variations of leaf epidermal features existed at the species level, such as shape and wall thickness of longcells, presence or absence of shortcells and its shape, distribution of stomata and shape of subsidiary cells, distribution of pricklecells, and shape of silicacells distributed in costal zone. The micromorphological study revealed that the characters of leaf abaxial epidermis could provide evidences for classification of the genus Poa. Moreover, the evidences of leaf abaxial epidermis confirmed the view that P. pratensis subsp. angustifolia and P. pratensis subsp. alpigena were the subspecies of P. pratensis subsp. pratensis.