The aims of this study were to determine the effects of Erabu sea snake Laticauda Semifasciata, a marine reptile, oil on plasma and liver lipids and plasma glucose in mice. Male mice (6 months old) were fed a diet containing 5% lard, 5% Erabu sea snake oil, or 5% fish oil mixture, which had the same percentage of docosahexaenoic acid as the Erabu sea snake oil, for 4 months. The plasma and liver total cholesterol, triacylglycerol and phospholipid concentrations, and plasma glucose concentrations were significantly lower in mice fed the sea snake oil diet than in those animals fed the lard diet. There were no significant differences in plasma and liver lipid components between the lard and fish oil mixture diet groups. There were no marked differences in plasma or liver fatty acid composition between the animals fed sea snake oil and those fed the fish oil mixture. These results indicate that a diet of Erabu sea snake oil has a lowering-effect on plasma and liver lipids and plasma glucose in mice and is more effective than a fish oil mixture.