Callus and suspension cultures of Silybum marianum were derived and the growth and production characteristics were assayed. The maximal production of flavonolignans was achieved at the beginning of cultivation, i.e. on day 10 after inoculation in MS medium with alpha-NAA and on day 15 after inoculation in MS medium with 2.4-D with continuous growth of the culture. The content of silymarin in the plant drug was 3.05%, in the in vitro culture it was just tenths of percents. TLC analysis revealed that the spectrum of flavonolignans of the drug differed from the spectrum of flavonolignans produced by tissue cultures. No differences in the spectra of flavonolignans produced by the callus and suspension cultures were observed. The test for antioxidative activity against the DPPH-radical demonstrated marked antioxidative properties of substances produced by the culture of Silybum marianum.