In order to use the wood building materials in dwelling construction, uranium content measurements were performed by one of the alpha or fission track methods. The investigated samples were tree and rush samples, collected from different Romanian sites, situated in the vicinity of zones with human radioactive activities, such as: Sapantza, Izvorul Izei (North Romania), Omer and Periprava (Danube River Delta). We have examined the U atom distributions in these samples in order to detect any U contamination due to radioactivity. For each analysed sample, two U track micromappings were obtained in the two track detectors which were put in intimate contact with the sample during reactor neutron irradiations. The obtained track micromappings were studied by optical microscopy. The U distribution and content measurement results are presented and interpreted according to the present norms referring to maximum permissible values of U in building materials in Romania.