The aim of this doctoral dissertation was estimation of the antioxidant activity, polyphenol and mineral composition of black, green, herbal and fruit bagged teas. Heaving in mind the fact that different polyphenol compounds as antioxidants can react in vivo by various mechanisms, for determination of the total antioxidative activity was used several spectrophotometric tests (DPPH, ABTS, FRAP and RP) and electrochemical method - cyclic voltammetry. The antioxidant capacity of the analyzed samples was estimated using the antioxidant potency composite index (ACI). For identification and quantification of individual polyphenolic compounds, HPLC chromatography was used, and multi-element composition of bagged teas was determined by ICP-OES method. In order to differentiation analyzed bagged teas, methods of multivariate statistical analysis (PCA and CA) were used. In relation to the obtained results, analyzed bagged teas could contribute to the daily dietary requirements.