Introduction. Oxidative stress is an important risk factor in developing pathological conditions in human body. Numerous phenolic antioxidants in species of g. Hypericum have scavenging radical activities and are considered promising bioactive compounds for free radical pathologies related with chronic diseases (atherosclerosis, neurodegenerative disorders, cerebral and cardiac ischemia, and rheumatic disorders).   The aim of the study. The comparative determination of total phenolic content (TPC) in different species H. perforatum L. and H. elegans Steph and in various plant raw materials (Hyperici herba and H. flores) of the sp. H. perforatum L.  Materials and methods. TPC for analyzed samples was assessed by Folin-Ciocalteu method. The absorbance was measured at 765 nm with Meterthech UV/VIS SP 8001 spectrophotometer. As solvent it was used 80% ethanol. The antioxidant activity was determined by DPPH and ABTS assay. The results are calculated in terms of gallic acid equivalent.  Results. The total content of polyphenols in dry extracts was determined: Hyperici flores – 42,76 mg/ml, Hyperici herba – 23,89 mg/ml, H. elegans aerial parts – 23,14 mg/ml.   The antioxidant potential determined by DPPH method showed: 11,65 µg/ml – H. flores; 19,08 µg/ml – H. herba; 19.95 µg/ml – H. elegans). ABTS method showed: Hyperici herba – 22,75, H. flores – 28,73 and H. elegans – 22,39 mM TEAC.  Conclusions. The most quantity of phenols is contained in Hyperici flores, which contributes to higher antioxidant activity. However, the content of phenols in aerial parts of both species of g.Hypericum are almost the same. This should be taken in account, because of the possibility of using Hypericum elegans as a medicinal plant.