Abstract:The microcharacteristics of leaf surface in Lysimachia were investigated by using light microscope (LM) and scanning electron microscope (SEM). Based on the features of leaf surface, those plants were obviously classified into two types, heterogenea-type and capillipes-type. The features of leaf, such as the presence or absence of the glands, the color and distribution of the glands, and the ornamentation of adaxial side, are quite constant at intraspecific level, but remarkably varied at interspecific level, which might have significant taxonomic value for species identification. In the 21 investigated species, 1 species was from Subgen. Idiophyton, 11 species from Subgen. Lysimachia, and 9 species from Subgen. Palladia. Since 2 types of leaf surface structure were found both in Subgen. Lysimachia and Subgen. Palladia, they could not be used as the characters to define subgenus.