Abstract: The epidermis of culm of S. alterniflora, S. patens and S. cynosuroides is all made up of long cells, short cells (cork cells and silica cells), salt glands and stomatal apertures. They are arranged alternately in longitudinal rows. The structure of salt glands is similar to that of S.anglica. But the number of the salt glands and the stomatal apparatus is different in these three species, especially, they are more abundant in S.cynosuroides than the others. Their internal structures consist of air passages, vascular bundles of various size, ground tissues and sclerenchyma. However, the number of vascular bundles and the development of sclerenchyma are not uniform with each other. Both of S.patens and S.cynosuroides have highly lignified sclerenchyma cells. In contract, the sclerenehyma cells in S.alterniflora have little lignification. The vascular bundles of S.cynosuroides are more than the others.