Abstract:The micro-morphology characters of leaf epidermis of 12 species of Iris were examined under light microscope(LM). It is considerd that there are obvious differences in the characters of leaf upper and lower epidermis of I. dichotoma Pall., I. uniflora Pall. and I. typhifolia Kitagawa of themselves, but there are not differences among the other 9 species. The type of stomata of 12 species of Iris is diacytic type, stomata is randomly distributed. Guard cells are parallel to leaf veins where no stomata distribute. There are obvious differences among 12 species of Iris in the micro-morphology characters of leaf epidermis, which will provide bases for Iris classification.