Extract of folia and flores Aristolochia clematitis contains flavonoids and non-toxic. The extract has cytotoxic and cytostatic activity in normal animal cells. At concentrations of 15 mg/ml and higher, the extract results in 100% cell death of the Spev line. The number of dead cells of the Spev line as a whole increases with increasing concentration of the extract. The LC50 of the Kirkason extract was determined by the probit analysis method. LC50=7.24 mg/ ml. With an increase in the concentration of the extract, a marked decrease in the cell’s polymeric activity was observed.