We observed the leaf epidermal micro-morphology of 17 taxa of Iris through the scanning electron microscope, described systematically the micro-morphological features of leaf epidermis, and made comparative analysis in the classification. The results indicate that, among different taxa, the morphology of epidermal cells in leaf epidermis, stomata and epidermal papillae are of certain taxonomic significance. In Iris genus, most epidermal cells are diamond-shaped, of which some short-diamond-shaped epidermal cells are of the original type. Stomatal apparatus is of irregular type. Stomata and anticlinal walls have concave or convex types. The pattern of anticlinal walls is straight or arched. The surface gaps around concave stomata are oval, square or diamond-shaped. Some taxa have papillas on epidermis, and are of polymorphism. These traits have no direct relations with the habitat of Iris taxa. The research also explored the taxonomic relations among subgenera and some allied taxa in terms of the micromorphological features of leaf epidermis.