Abstract: In the small veins o f the three species of rattan,the bundle sheath mayhave two distinct layers of cells.The outer sheath(OS)consists of a layer ofendodermoid cells,While the inner sheath(IS)may have one or several layers of thick-walled cells. Both OS and IS were described at ultrastructural level in this paper.Finally,problems related to the anatomy of the Palmae and Gramineae in the refere nces were discussed.