SummaryEffects of L-ascorbate 2-sulfate (AAS) on fatty liver and hyperlipidemia induced by various treatments were studied in rats and guinea pigs. L-Ascorbic acid (AA) (50 or 175mg/kg), a reference compound, lowered the lipid levels in the serum and/or liver in guinea pigs, while AA had little effect in rats. On the other hand, AAS (300 mg/kg) was effective in both animals . In rats, AAS lowered cholesterol and triglycerides in the serum from ethionine-treated animals and in the liver from orotic acid-supplemented animals . In guinea pigs, this compound lowered cholesterol and triglycerides in the serum from ethionine-treated animals, lipids in the liver from cholesterol supplemented animals, and lipids in the serum and liver from scorbutic animals. AA markedly increased the content of AA in the organs in all experiments, while AAS had a slight effect . Thus, it is suggested that AAS exerts its hypolipidemic and lipotropic effects by the specific actions of AAS.