Abstract: This paper is attempted to study the leaf epidermis about 15 species of Chinese Setaria by current method. The results of our study are summarized as follows:1. The six groups of the structure of leaf epidermis are equal to the six sections of the structure of inflorescence and spikelets in Setaria. 2. The long-cells of different shape, size and the nature of their wall can show the features to divide the subtribe, genus or species exactly. 3. In the structure of leaf epidermis of Setaria especially the shape of the long-cells, the section of Ptychophyllum (A.Braum) Stapf should be as an independent section, the section of Setaria is similar to section Paurochaetium (Hitchc. & Chase) Pilger, section Pennisetoides Tzvel, and section of Panicatrix Stapf, the section Laxispiculosae S. L. Chen et G. Y. Shang is similar to section Pennisetoides Tzvel. by its adalial epidermis and similar to section Sctaria by its abaxial epidermis.