This work shows the in vivo effect of the bioactive triterpenoid betulonic acid on the liver of C57BL/10 mice and the functioning of the mitochondria of this organ. We have found that betulonic acid has no significant effect on the histological parameters of the mouse liver, as well as on the biochemical parameters of the blood serum of the studied animals. At the same time, betulonic acid has demonstrated mitochondrial targeting. Betulonic acid has shown a decrease in the functional activity of mitochondria, especially in the case of their energization with succinate, a substrate of complex II of the respiratory chain of organelles. Treatment with betulonic acid has no effect on the resistance of mouse liver mitochondria to the induction of a calcium-dependent MPT pore. On the other hand, we have revealed the antioxidant effect of betulonic acid associated with a decrease in the rate of H2O2 generation in the mouse liver mitochondria. The paper discusses the possible use of betulonic acid as a mitochondria-targeting agent.