Background. The cell developed a series of antioxidant agents which protect it against harmful effects of free radicals. The superoxide dismutase (SOD) by a redox reaction converts superoxide anion (O2−) into oxygen and hydrogen peroxide. The last can also damage important cells‘ structures, therefore is degraded by enzymes such as catalase (CAT), found in peroxisomes. The roots of Taraxacum officinale (TO) are rich in phenolic and terpene compounds, sesquiterpene lactones, fructosans and inulin, which alone or in combinations demonstrated great antioxidant abilities. The aim of present research was to assess the influence of different TO roots (TOR) ethanolic and dimethyl sulfoxide (DMSO) extracts on red blood cells (RBCs) SOD and CAT activity. Material and methods. The TO were harvested from a natural habitat in Republic of Moldova. The extracts for analysis were prepared from grinded dried roots (2 weeks at room temperature). DMSO and ethanol of different concentrations (20, 25, 40, 50 and 80% (v/v)) were used as solvents. The influence of TOR extracts on healthy persons RBCs‘ SOD and CAT activity was evaluated in accordance with Ryzhikov S.L. et al. (2011) method, modified by Gudumac V. et al. (2010, 2012). The statistical analysis included calculation of mean and standard deviation (M±SD), Mann-Whitney U test (control vs experimental groups) and Spearman (rs) correlation (ethanol concentration vs enzymes activity). The p-values equal or less than 0.05 were considered statistically significant. The study was approved by the Research Ethics Committee of the ―Nicolae Testemitanu‖ State University of Medicine and Pharmacy. Results. SOD activity was dependent on the type of extractant. The ethanol concentration of the extract did not statistically significantly correlate with the influence of TOR on SOD activity (rs=0.087, p=0.38); nevertheless an increase in the enzyme activity was found in comparison with the control values for all TOR extracts (10% – 33.94±1.83* (+10.1%), 20% – 36.08±0.86* (+25.5%), 25% – 31.4±0.48* (+3.5%) 50% – 42.23±1.66*(+54.9%), 80% – 38.02±0.65* (+23.3%), except 40% (26.25±0.68* or -9%). DMSO extracts determined an increase in RBCs SOD activity (50.10±10.73* or +83.9%). A strong negative correlation was identified between ethanol concentration and CAT activity in RBCs (rs=-0.73, p=0.001). DMSO (26.17±9.84* or -42.3%) and all TOR alcoholic extracts (10% – 55.06±4.52 (-21.7%), 20% – 48.04±0.73*(-13.3%) 40% – 41.72±0.16 (-7.3%), 50% – 41.88±11.67 (-15.6%), 80% – 41.71±2.49 or -11.4%), except 25% (56.12±3.26* or +47.5%), reduced the CAT activity compared to control values. Conclusion. Taraxacum officinale roots act as potent modulators of the antioxidants system, affecting SOD and CAT activity. This action depends on the type of solvent. The greatest stimulating effect on SOD activity are exerted by the TOR extracts in DMSO and 50% ethanol. The increase of alcohol concentration in extracts diminishes CAT activity, except extracts in 25% ethanol. Further studies are needed to elucidate the mechanisms of TO influence on the antioxidant system.