The data of Agrobacterium-mediated transformations of some Linum usitatissimum cultivars located in the territories of Belarus and Ukraine with the plasmid carrying of the chimeric GFP-TUA6 gene and the nptII gene as selectable markers conferring resistance to kanamycin are presented in this study. The transformations were affected by a number of factors, including optical density (OD600), inoculation time of explants with Agrobacterium, and coculture conditions. The transgenic nature of the obtained lines was confirmed by PCR analysis. Expression of the GFP-TUA6 gene was detected by confocal laser scanning microscopy. The obtained transgenic lines can be used for further functional studies into the role of microtubules in the processes of building flax fibers and resistance to wind.