The aim of this work was to measure the antiradical activity of plant extracts and plant raw materials with use of TAU734 (total antiradical unit). For the study, three raw materials were used: oak bark (Quercus cortex) rich in tannins, inflorescence of hawthorn (Crataegi inflorescentia) rich in flavonoids and seeds of coffee (Coffeae semen) rich in phenolic acids (caffeic, chlorogenic acids). The methanol-water (1:1) extract was obtained from each raw material. A part of the extract was evaporated under reduced pressure to obtain dry extract A. The remaining part of methanol-water extract was submitted for further extraction and evaporation in order to obtain final dry extracts B (precipitate), C (ethyl acetate) and D (remaining aqueous). The antiradical activity was measured using ABTS•+ radical (2,2’-azino-bis (3-ethylbenzothiazoline- 6-sulfonic acid) diammonium salt). Antiradical potential was demonstrated as a number of antiradical units per mg of extract (TAU734/mg) and g of raw materials (TAU734/g). The highest number of antiradical units per g of raw material (TAU734/g - 13837±1726) was noticed for bark of oak. The weakest antiradical properties were observed for seeds of coffee (TAU734/g - 5929±856). The largest number of antiradical units (TAU734/mg - 99.6±15.9) was noticed for mg of extract Bo from bark of oak. The weakest antiradical properties (TAU734/mg - 16.0±2.0) exhibited extract Bc from seeds of coffee.