Abstract: By applying electron microscopic technique, we aimed to observe the morphology of leaf cell vacuole of Stevia rebaudiana Bertani, and the change of inclusion during its different stages of growth. We ascertain that the size of vacuoles is small in younger leaf cell, that the number of vacuoles is more than that in other stages, and that vacuoles appear translucent, either round or elliptical in form. Also those leaf cells that are at the stage of active growth appear to have many morphologically specialized vacuoles containing a lot of inclusions in different forms of granule and vesicle. Furthermore, the inclusion of the vacuols in the elder leaf cells decompose gradually, eventually disappear. Comparing with the substructural observation of chloroplast, by PAS reaction, and with different content of steviaside, we discover that there exists corresponding relationship. Thus, we may infer that steviaside is stored mainly in the vacuoles and it is relevant with the function of production.