Abstract: Oleanolic acid, a triterPenoid, caused a dosedependent liver damage in mice at the dose up to 80 mg/kg per day S. C., manifested by rise of SGPTactivity, loss of body weight, prologation of sleeping time, increase of liver weight, and decrease of the level of cytochrome p-450 in liver homogenate.Oleanolic acid could not protect the liver from damage induced by CCl₄ in mice, but instead enhence it at a high dosage.