The aim of this study was to investigate the effects of herbal remedy using onion (HRO-1) supplementation on body weight change and cholesterol, triglyceride. free fatty acid, total lipid, phospholipid serum level in obesity mice. This study classified 32 of 4 weeks-old male C57BL/6 mice which have obesity caused by high fat fed into four groups of 8 mice and made the subjects medicated them HRO-1 for 6 weeks. Male C57BL/6 mice were divided into four groups; a normal group, a high-fat group, a high-fat group supplemented with HRO-1 (500 mg/kg), a high-fat group supplemented with HRO-1 (1000 mg/kg). In respect to the body weight change, there was statistically significant difference between the HRO-1 (1000 mg/kg) group compared to high-fat group (p<0.05). In the total cholesterol and LDL cholesterol level, there was statistically significant difference between the HRO-1 (1000 mg/kg) group compared to high-tat group (p<0.05). In the triglyceride and free fatty acid level, there was statistically significant difference between the normal group compared to high-fat group (p<0.05). In the total lipid and phospholipid level, there was statistically significant difference between the normal group compared to high-fat group (p<0.05). Also in the total lipid level, there was statistically significant difference between the HRO-1 group compared to high-fat group (p<0.05). The above results suggests that HRO-1 medicated is effective to prevention and treatment of obesity.