Abstract: Structural characters of leaf epidermis from 9 species in Iris from the North of China, such as the epidermal cells, the distribution of stomata, density of stomata and the stomata index, were investigated using light microcopy (LM), which aimed to study their taxonomic values between subgenus and subsection. The shape and size of the epidermal cells has taxonomic value that manifests the genetic relationship between different species,and has much systematic significance in distinguishing within difffenent section and subgenus in Iris L. Density and index of stomata has no systematicsignificance in distinguishing within subgenus in Iris L., but it can reflect their living environment. And from the results of epidermal structure,it confirmed a strong
genetic relationship between I. dichotoma and Belamcanda chinensi,consistent with other anmatomy of leaves such as:vascular,the cross shape of leaf,stomata,crystal,mesophyll protoplast,size of gas chamber which reflect the connection between microstructure and living environment were also discussed.

Key words: Iris L., leaves, epidermal structure, anatomical structures, taxonomic values, habitat