Abstract: The leaf micromorphology of eleven species and one variety from four genera of Polypodiaceae subfam.Polypodioideae in China were observed and compared under light microscopy(LM).The epidermal cells of Polypodioideae were irregular,with the anticlinal walls sinuous to sinuate.The stomatal apparatus in all species only existed on the abaxial epidermis.The major stomatal apparatus were polocytic,copolocytic,axillocytic,coaxillocytic,anisocytic,anomotetracytic,and anomocytic types.The stomata on a single leaf belonged to two or more types in all species.Based on leaf micromorphology,the relationships between Metapolypodium and Polypodium,P.wattii and P.niponica,P.microrhizoma and M.manmeiense are also discussed.