Wood is a versatile tissue complex composed of different cell types such as tracheids, fibers, vessels and parenchyma cells, that each fulfills specific tasks within the woody body of a tree. However, even within a tree genus wood structure can differ significantly due to either biotic or abiotic stress factors occurring during the growth season, or due to cultivar specific growth characteristics. Typical tools for structural analysis of wood so far are scanning electron microscopy (SEM) and light microscopy, allowing measurements of sectional planes. However, the detection of boundary surfaces between neighboring cells and interconnectivity can only be observed in a restricted dimension. In our investigations at DESY, Hamburg, we applied SRμCT for characterization of small wood samples of poplar (Populus trichocarpa) to gain a three dimensional image of a small scale sample that allows us to visualize size, volume, form and interconnectivity of the cells in a non-destructive way. Dependent on sample size, high resolution of micro-structure can be gained. This technique is appropriate to calculate volumes, e.g. of water transported in vessel cells. Since it is possible to reconstruct the vessel network within a stem section, effects of wounding or other environmental stresses on the xylem structure in general, and particularly on the water transport system, might be detected and visualized in 3D by synchrotron radiation-based microtomography. Hence this method is a most promising tool for future investigations in the field of plant physiology.