Amino acids from plants have an important influence on various systems and organs of the human body. They have broad pharmacotherapeutic properties, promote faster absorption of biologically active substances and potentiate their action. Brassica oleracea L. ( Brassicaceae family) common vegetable plant that has long been used in folk medicine to treat many diseases. Therefore, it is important to determine the qualitative composition and quantitative content of amino acids in cabbage leaves. Amino acids were identified in the cabbage leaves of different cultivars by ion-exchange liquid chromatography. The total number of amino acids was 18 and 7 of them are essential and 2 are conditionally essential amino acids. Glutamic acid and proline were dominant in Bilosnizhka cultivar (1.74% and 1.26%), Yaroslavna cultivar (1.24% and 2.31%), Ukrainian autumn cultivar (2.49% and 1.55%) respectively. Methionine and γ-aminobutyric acid have been found in minorities in all samples of cabbage leaves: Bilosnizhka cultivar 0.07% and 0.10%; Yaroslavna cultivar 0.11% and 0.01%; Ukrainian autumn cultivar 0.07% and 0.11% respectively. The highest sum of amino acids was in the cabbage leaves of Yaroslavna cultivar (10.73 %).