The Pteridaceae has been variously classified by different taxonomists. The leaf epidermal morphology of 48 species in 11 genera of Taiwan Pteridaceae was studied using SEM. There are six types of trichomes, two types of adult stomata and three types of epidermal morphology described. And the variability of some epidermal characters, such as the stomata flush or sunken, the long axes of epidermis cell lie parallel to the vein or not, the lines on cells or not, could distinct part of genera and subfamilies. Based on previously described characters, the epidermis pattem of Cheilanthes could be divided into four types, the cheilanthes type, the aleuritopteris type, the mildella type and the doryopteris type; and that of Adiantum could be divided into two types, branched type and nonbrached type. And the epidermis morphology of Coniogramme was very simility to that of Pteris. Besides, the epidermis characters showed that Cryptogramma, Onychium and Acrostichum are unique. And more study of the three genera is needed to understand the relationships among these genera.