Abstract:Rhododendron L. is a large genus of Ericaceae and widely distributed in Eurasia and North America. The infrageneric classification of Rhododendron is acontroversial issue due to a large number of variations andtransitional characters. Micromorphological characters of leaf epidermis from 11 species and 3 varieties of subsect. Maculifera, subgen. Hymenanthes were examined using scanning electron microscope (SEM). The result shows the following characters: the adaxial lepidermis surface is smooth or rough, no foliar trichomes, ornamentations include strips, branching and short rod shapes; the abaxial epidemis surface has branching waxy ornamentation or not, some have foliar trichomes, without fingers of protuberance or eglandular. The stomatal apparatus are round or oval, with rough or smooth inside and outside the stoma, but without interrupted strip or other abnormal ornamentation around. The above micromorphological characters show certain similarities and differentia, which could provide new evidence for classification and evolution researches. Based on micromorphological characters of leaf epidermis, keys are generated, and then the taxonomic use of these characters in affinitive species and infraspecies are also discussed.