We conducted experiments to establish the growing conditions of hydroponic young green barley plants in which functional ingredients were applied and absorbed during the cultivation period. No studies have conducted experiments on functional ingredients applied during the cultivation of young green barley. In this study, glucosamine (GlcN) and collagen (Cgn) were used, both of which are widely known as functional ingredients and are in high market demand. In the GlcN application experiment, young green barley plants were cultivated with only liquid fertilizer during the early growing period for 9 days, and then the plants were cultivated in 0.25% GlcN-water solution for the following 3 days. The plants used in this experiment absorbed 0.60% of GlcN. Furthermore, an experiment was conducted to test plant absorption of collagen. Collagen absorption was evaluated using hydroxyproline (Hyp) as an indicator ingredient. Under control conditions, the Hyp content was 0.04% after 14 days of cultivation. Meanwhile, in the application experiment of Cgn derived from pigs (average molecular weight is 3000), plants were cultivated in 1% Cgn-water solution for 14 days. As a result, the Hyp content increased to 0.28%. Thus, this study clarifies, for the first time, that barley plants can absorb exogenous functional ingredients applied from the outside. The nutrient component contents in young green barley plants were measured. The amino acid and vitamin C content in hydroponic young green barley significantly increased, as compared to those grown in organic soil. Furthermore, in 0.1% Cgn-water solution cultivation, glutamic acid and aspartic acid, both of which are a functional amino acids, increased approximately three folds as compared to the plant grown in organic soil under natural sunlight. Furthermore, K and Na, which are inorganic ingredients in young green barley, were measured. The K content in the plants grown in 1% Cgn-water solution cultivation for 14 days decreased by 80% as compared with the control hydroponic plant grown with liquid fertilizer. It was inferred that the plant might be used as food for dialysis patients.