Background : Diabetes is a chronic disease characterized by deficiency of insulin. It has been reported that Fructus aurantii and mulberry leaves have the effect of anti-diabetes. Methods : To investigate the improvement of mixed extracts of Fructus aurantii and mulberry leaves on lipid metabolism, we performed double-blinded, randomized and placebo-controlled multi-center clinical trial. Results : Mixed extracts of Fructus aurantii and mulberry leaves significantly reduced total cholesterol. Conclusion : These results suggest that mixed extracts of Fructus aurantii and mulberry leaves improve lipid metabolism.