Akebia saponin D (ASD) is a typical bioactive triterpenoid saponin obtained from the rhizome of Dipsacus asper Wall. Previous studies have found that ASD has a hepatoprotective effect in a mouse model. The purpose of this paper was to explore the molecular mechanism of the hepatoprotective effects of ASD on BRL cells and isolated rat liver mitochondria. We investigated the effects of ASD on rotenone-induced toxicity in BRL cells. The results showed that ASD inhibited the accumulation of reactive oxidant species, ATP deficiency, and mitochondrial membrane potential dissipation; ameliorates mitochondrial respiratory dysfunction, and improved the activity of complex I in a concentration-dependent manner, indicating that ASD likely improved mitochondrial function. ASD suppressed rotenone-induced BRL cell apoptosis and increased Bcl-2/Bax ratio. These results suggest that ASD may exert hepatoprotective effects against rotenone-induced toxicity through mitochondria. This study supports our previous research that ASD possesses hepatoprotective activity in vivo and it is worthy of further study.