Invasive species are becoming an ever-bigger challenge in nature. In this rapidly changing climate, they are overrunning native species even faster. The wood properties of invasive species in general are poorly studied, but if we are to include such species in our production chains, then knowledge of these properties is fundamental. The majority of invasive species are not resistant to blue staining and moulding, and therefore their wood needs to be treated, if it is going to be used in an outside environment. In this master’s thesis we explore and test the impregnability and fixation of copper based active ingredients to selected invasive wood species. We determine their density and study how thermal modification effects the previously mentioned abilities. We conduct a variety of tests in which we try to determine how resistant invasive species actually are to blue stain fungi and moulds. In our experiments we have shown that wood mass and anatomy effects the impregnation and fixation abilities of wood. Thermal modification of the tested invasive species resulted in density decrease. Permeability after modification is increased. With the exception of Robinia pseudoacacia and Gleditsia triacanthos, we have learned that all other tested species are not at all resistant to blue staining fungi and moulds. Their resistance is similar to that of the sapwood of Pinus sylvestris.