Objects : There was an increase in obese population due to eating habits resulted in modernization of lifestyle and the change of the tendency to conduct the physical activity, in order words, the reduction in the range of kinetic energy. Obesity is viewed as a major risk factor for serious health problems, including heart disease, high blood pressure, stroke, diabetes, and certain forms of cancer as well as for psychological and social problems owing to our fat-phobic society. In the present study, we investigate the weight loss thanks to giving Handayulso-tang(HD) medication of Taeum-in to induced obesity rats and its effects on lipid metabolism, given that their behavior patterns are changed according to their constitution. Methods : The extracts of Handayulso-tang was orally administered to the rats of HD group 200mg/200g of rats weight every day for 6 weeks, and the control group were fed with equal amount of saline. And measured the body weight and total cholesterol, triglyceride, free fatty acid and total lipid contents in serum in obese rats. Results : 1. The body weight in HD group were decreased. 2. The contents of serum total cholesterol and triglyceride in HD group were decreased and statistically showed the significant difference compared with the control group. 3. The contents of serum free fatty acid and total lipid in HD group were decreased, but did not statistically show the significant difference compared with the control group. Conclusion : Based on the above results, we know that Handayulso-tang have effects on the decrease of the body weight and the contents of serum total cholesterol, triglyceride, free fatty acid and total lipid. So it could be concluded that Handayulso-tang can help the treatment of obesity.