Abstract:The observation by transmission and scanning electronic microscopy on the endosperm cells from mature and developing seeds of Sesbania cannabina shows that the Sesbania gum after its synthesis is not secreted out of cells, it is accumulated inside the cells. The viscosity determination of different size of granules demonstrates that, the larger the size of granules, dm lower the gum viscosity, on the contrary, the smaller the size, the higher the viscosity. This result is in agreement with the localization of gum inside the cells. In addition, the total Content of saccharide and insoluble substances for different size granules was also determined, These results provide the need of small size of gum granules in the process of production with tile evidence of gum localization inside the endosperm cells of Sesbania seeds.