This paper deals with macroscopic and microscopic observation and with measurement of xilem elements (fiber and vessel members) of wood stem of Scleronema micranthum Ducke (Bombacaceae Family) from Amazonia region. As this wood does not show any grows rings, the wood was separated in radial direction in five zone for maceration of theses elements. The first zone correspond the sapwood and the other four zone the heartwood. From macroscopic and microscopic examination the author verified that this wood has uniform structure. By statistical analysis of variance the following conclusions was take: first, there is no significative variation between datas in the diferents zones. But one only exception was verified with the width of vessel members which increace its width from medium zone to inside and outside zones of the wood; second, the longest fiber has highest thickness wall (signification 1 %o third, the fibers length has 4,5 increase relatede with the vessel elements length. This point out this elements had a intrusive groing, and so no related with cambial activity.