One of ways to increase resistance of agricultural plants to abiotic stresses is the use of biofertilizers with anti-stress and growth-regulating properties. They improve absorption of nitrogen and phosphorus from organic fertilizers and soil. The purpose of the research was to study sowing qualities of seeds, morphological indicators of spring barley seedlings after presowing seed treatment with biofertilizers under conditions of sufficient humidification and osmotic stress. The laboratory experiment was carried out to study the effect of biofertilizers on seedlings of spring barley ( Hordeum vulgare L.) cv. Gubernatorsky under conditions of sufficient and insufficient humidification. The barley seeds were treated once according to the following scheme: 1. control (distilled water) 10 L/t; 2. Gumi 20 M potash (0.4 L/t); 3. Borogum-M complex (0.2 L/t); 4. PEG 6000 (100 g/L); 5. Gumi 20 M (0.4 L/t) + PEG 6000 (100 g/L); 6. Borogum-M complex (0.2 L/t) + PEG 6000 (100 g/L). Treatment of spring barley seeds with biofertilizers increased the germination rate and germination capacity by 35 and 2 %, respectively. When modeling drought using PEG-6000, the sowing qualities of seeds decreased by 4 %. Under conditions of sufficient humidification, the studied biofertilizers had a complex positive effect on shoot and root weight of barley seedlings. In addition, the average length of roots, shoots and the total root length increased. The number of roots did not change significantly. Lack of moisture decreased the effectiveness of Borogum-M complex biofertilizer, while Gumi 20 M potassium biofertilizer had a positive effect on the parameters of barley seedlings under water stress conditions.