We investigated the effects of Acorus gramineus water extract on the blood lipid levels in high fat diet-fed obese male mice. We divided thirty-five C57BL/6 mice into 5 groups: normal group, control group, and groups treated with Acorus gramineus water extract at concentrations of 20, 100, and 500 ㎎/㎏. We inoculated Acorus gramineus water extract per orally once a day for 6 weeks respectively. The results revealed that Acorus gramineus water extracts had positive effects on the total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels.