Barley (Hordeum vulgare L. cv. "Rudzik") seeds were soaked in aqueous 10^-6 M 4-hydroxyphenethyl alcohol (4-HPEA) to estimate its influence on seed germination, growth of seedlings, and their adaptive potential under soil flooding conditions. The adaptive potential of the plants was estimated by the concentration of thiobarbituric acid reactive substances (TBARs) and the activity of guaiacol-dependent peroxidase (GPX). It was shown that the 4-HPEA had a stimulatory action on seed germination, shoot and root growth, and biomass production, expressed to a greater extent in the early stage of plant development. Pre-sowing soaking of barley seeds in aqueous 4-HPEA solution increased plant tolerance to the effect of soil flooding, too.