Wheat grass is a young shoot of the Triticum genus, which in large quantities contains chlorophyll, bioflavonoids, essential amino acids, vitamins, minerals and antioxidants. Natural antioxidants are vitamin C and E, carotenoids, flavonoids anthocyanins, betanins, and polyphenolic compounds that are widespread in the plant world. The aim of the study was to determine whether the storage of wheat grass and the length of storage significantly influence the change in antioxidant capacity in the juice or leaf of wheat grass of the wild relative Triticum aestivum ssp. sphaerococcum. Antioxidant activity in juice extracts and leaf tissue was measured immediately after harvesting and after storage at three different temperatures (4°C, -18°C, -80°C) after 1, 7, 14 and 21 days of storage. The results of the study confirm that antioxidant capacity decreases very rapidly in juice, at any storage temperature and regardless of the length of time. On the other hand, in leaf tissue, the antioxidant capacity remains unchanged even at 4°C after 24 hours of storage. In leaf tissue, DPPH activity declines after 7 days of storage compared to control, however, there is no significant decrease in DPPH values between 7th and 21st day of storage. From the nutritional point of view and the amount of antioxidants we ingest, it is healthiest to consume fresh leaf on the day of harvest. Already by the preparation of the wheatgrass juice, the DPPH value falls, and the reason may be the depletion of antioxidants due to the destruction of cell membranes and the change in the oxidoreductive potential caused by the drop in pH. From the analytical point of view, if we are storing the sample, it is best to store the leaf at lower temperatures and to do the analyzes no later than one day after harvest.