Abstract:Comparative micromorphology of the leaves of 2 species and 3 populations in Melampyrum from Anhui were studied with epidermal maceration,electron microscope and paraffin section method.The results are as follows：the shapes of leaf epidermal cells which have chloroplast, are irregular and the anticlinal walls are sinuous,sinuate, or double-sinuate, the cuticular membrane of leaf epidermis is striated; Both trichome and glandular are on the epidemis,the trichome has neoplasitic process under SEM. The palisade tissue consists of only one lay cells which line up loosely,and the spongy tissue has developed interstitial space; The stomatal apparatus which only distribute in lower epidermis are mainly of anomocytic type,but few concur to have only one accessory cell. Under SEM observation, the inner margin of outer stomatal ledge is near smooth or sinuolate. The results show that the significant micromorphological differences among two species are the pattern of anticlinal,the density of trichome,the length and width ration of stomatal apparatus, the ratio of palisade tissue to apongy tissue and the characters of middle veins,but there are not many differences among 3 populations of Melampyrum roseum.