Copper-ethanolamine based preservatives are one of the most important wood preservatives for protection of wood in third and fourth use class. Despite the fact that they are commercially used for several years, complete mechanismof fixation in wood has been not resolved to date. It is clear that copper-ethanolamine system reacts with wood faster than copper-chromium based wood preservatives. It is not known, however, which parameters control this process of fixation and when it is finished. Influence of impregnation time, wood species (Norway spruce, beech), temperature and concentration of commercial copper-ethanolamine preservative solution Silvanolin on copper adsorption to wood particles is elucidated in this contribution. Concentrationof copper in wood particles was determined with X-ray fluorescence spectroscopy (XRF). The results confirmed that the reaction of copper-ethanolamine complexes in wood is a fast process. During the initial six hours of impregnation, between 60 and 80% of retained copper is adsorbed in wood. Copper adsorption is increasing with increasing concentration as well, and it can be significantly improved with impregnation at 50°C.