The hepatoprotective effects of new triterpene derivatives, betulin 3β,28-di-O-nicotinate (of3) and 3,20-dioximino-29-norlup-28-ic acid methyl ester (of15), were studied in CBA/Lac mice with transplanted RLS lymphoma receiving polychemotherapy and without it. Injection of of3 and of15 agents to animals with tumors receiving polychemotherapy reduced the severity of toxic involvement of the liver, reduced mitotic activity of tumor cells in the primary node in animals receiving and not polychemotherapy, and produced a moderate antitumor effect. These effects were more pronounced for of15 agent. In addition, injection of agents of3 and of5 to animals with transplanted RLS lymphoma reduced the intensity of alterations associated with the total systems and local effects of the neoplastic process.