The paper presents the results of experimental research on the peculiarities of the chemical composition of kohlrabi varieties ‘Azur’, ’Videnska Synia’, ‘Videnska Bila’ and ‘Hihant' cultivated in field conditions in the Forest Steppe of Ukraine. The goal of the research was to track changes in the biochemical composition of kohlrabi under the effect of varietal factor. The experiment was carried out in the years 2018−2021. It was found that the vegetation period of the variety 'Hihant’ is 145 days, while the vegetation period of varieties ‘Azur’, ‘Videnska Synia’ and ‘Videnska Bila’ ranges between 60 and 80 days. As a result of the longer vegetation period, ‘Hihant’ overcomes other varieties under study by the content of water (88.7%) and dietary fiber (2.1 g/kg). Kohlrabi variety ’Videnska Synia’ is the most suitable for dietary nutrition, since it has a higher content of vitamins A, B1, B9, B4, C, B3, and essential amino acids, such as arginine, valine, histidine, isoleucine, leucine, lysine and phenylalanine, compared to other varieties. The content of linoleic, linolenic and palmitic acids is also the highest in ’Videnska Synia’. However, the content of vitamin B6 is the highest in ‘Hihant’.