In this study, we investigated the effect of seatangle drink and seatangle extract product on weight gain and serum and hepatic lipid composition in rats fed a hyperlipidemic diet. In the dietary hyperlipidemia induced rats, it was observed that serum triglyceride, phospholipid, total lipid, LDL-cholesterol level and atherosclerotic index were higher, while the HDL-cholesterol level was lower when compared to the normal group. Total hepatic lipid and cholesterol content of the dietary hyperlipidemia induced rats was conspicuously decreased by seatangle drink and seatangle extract product treatment. Especially, triglyceride content was decreased to 30% by seatangle drink treatment, and 45% by seatangle extract product treatment.