Background: It is known that 60-80% of the population affected by various diseases, such as heart attack, stroke, and oncological diseases is associated with selenium (Se) deficiency. Therefore, enriching agricultural crops with Se is considered a current issue. Objective: This study investigates Se enrichment of Lycium barbarum (Lb) and its effectiveness in hydroponic and soil conditions in the Ararat Valley. The research focuses on the impact of adding exogenous Se on plant productivity, Se accumulation, and the content of biologically active substances (BAS) in Lb berries and leaves. Methods: The experiments were conducted from 2021 to 2023 using hydroponic and soil cultivation methods with varying Se concentrations in nutrient solutions and foliar nutrition. Results: The results demonstrate that Se enrichment significantly increased Se and BAS levels in both leaves and berries of Lb, with hydroponic cultivation exhibiting higher accumulation compared to soil conditions. Foliar feeding with a 0.005% Se solution and exogenous Se addition to nutrient solutions at 1.0 mg/L resulted in notable improvements in Se content and plant productivity. Furthermore, the analyses revealed significant differences between hydroponically and soil-grown Lb, emphasizing the potential of hydroponic cultivation for producing Se-enriched plant material with enhanced BAS content. Conclusion: Hydroponic cultivation supplemented with Se and foliar nutrition is recommended for obtaining Se-rich Lb plant material, which is suitable for medicinal and functional food purposes. These findings contribute to the development of biotechnologies for Se -enriched plant production and addressing health and nutritional needs. Keywords: Goji, berries, biologically active substances, flavonoids, phenolic acids, tannins, carotenoids