Abstract:In order to solve the taxonomic problems of Orchidaceae Pleione and explore the significance of leaf ultrastructure in taxonomy, this study uses scanning electron microscopy to investigate 15 mature leaf epidermal ultrafeatures of 15 Pleione species such as cell boundaries, cuticle and stomatal apparatus restrict and et al, and to determine their taxonomic significance. (1) Cell boundaries, epidermal cell wax quality, stratum corneum texture, stomatal distribution, wax around the stomatal, inner edge of the outer arch of the stomatal, keratinization, relative height of the stomatal, epidermal cell length, epidermal cell area and guard cell length, these 9 indicators of guard cell area are of great value and significance for the classification of this genus. (2) Using these indicators could distinguish S. Humiles S. Pleione and P. bulbocodioides complex. (3) The cluster analysis clustered 15 species of Pleione into four branches, which is basically consistent with the results of traditional taxonomy and molecular systematics. P. × taliensis Cribb & Butterfield has many indicators same with P. yunnanensis (Rolfe) Rolfe and P. forrestii Schltr., their relationship need further research.