Aim. To investigate the level of resistance to salt stress of T3 and T4 seed generation plants of genetically modified wheat (Triticum aestivum L.) with an additional copy of the ornithine-δ-aminotransferase (oat) gene and their original genotypes. Methods. Determination of the content of free L-proline (Pro) and physiological and morphometric parameters. Results. The level of Pro was studied and the morphometric and growth parameters of the offspring of transgenic plants and their original forms under normal / stress conditions were analyzed. Conclusions. T3 and T4 wheat plants under salinity conditions had a higher percentage and higher rate of seed germination compared to the original genotypes. During in vitro cultivation of seedlings, a stress state was observed at doses of 250 and 300 mM NaCl, at which the percentage of survival of transgenic variants was 83.3, non-transgenic only 33.3. Under conditions of in vivo salt stress, T3 and T4 plants had taller shoots and longer roots compared to the original forms. The survival rate of genetically modified plants was ~ 90 %, non-transgenic plants about 60 %. There was no significant difference in the accumulation of free L-proline between the investigated plant variants. It increased in transgenic seedlings on the 21st day of stress under conditions of artificially simulated salinity.