Abstract: Anatomical observation on the vegetative organs (root, stem and leaf) of Melientha longistaminea were made with microscope by means of paraffin-cut sections and integral loading methodology. It was showed by the observation that:The root of M. longistaminea belonged to meaty root system which would continuously grow in diameter. The primary xylem of vascular strand was tetrarch at the initial stage; along with the taproot thickening, bundles of the primary xylem became polyarch. The growth of vascular strand cambium was not significantly influenced by the change of seasons, with inconspicuous growth rings. There were two piths in the central part of the stems because of the secondary accretion of wood ray cells adjacent to the first pith center, forming large quantity of parenchyma cells. This species had solitary leaves, and the leaf epidermis cells were regularly geometric in shapes, with paracytic type of stoma and 2 to 4 subsidiary cells around each stomata.