Contemporary agrobiology is aimed at solving the problem of sufficiently stable agricultural crop yield, given the principles of eco-friendly nature use and mandatory monitoring of anthropogenic load on agrocenoses. Hormonal regulation of physiological functions, including the use of preparations based on phytohormones and modifiers of their activity, is one of the topical directions for tackling the problem of plant productivity. The article presents the research results of the effect of the inhibitor of antigibberellin action - chlormequat chloride - and the stimulator based on treptoleum phytohormones on the processes of morphogenesis, the formation of the photosynthetic apparatus, and the yield of flax plants. The plant height is established to decrease under the action of chlormequat chloride, and increase under the influence of treptolem. Both preparations caused an increase in the flax stem diameter. When applying growth regulators, the number of leaves and their total surface area, duration of functioning increased, which generally contributed to the improvement of the crop structure and flax plants productivity. Determination of the content of residual amounts of drugs was carried out on samples of leaves and stems of flax, while the complete absence or traces of chlormequat chloride was noted.