1.Purpose This study was researched in order to investigate the effect of Hyungbangdojucksan-Gami and Kamsuchunilhwan on the obesity in rats. 2. Methods The rats were divided into 10 groups - The normal group fed with normal diet. One of the sample groups fed with high fat diet, and since fifth week had fed with Hyungbangdojucksan-Gami. The other sample groups fed with high fat diet, and since fifth week had fed with Kamsuchunilhwan. The control group fed with high fat diet, and since fifth week had fed sodium chloride. 3. Results 1. The rate of increasing weight was significantly decreased after oral administration of Hyungbangdojucksan-Gami and Kamsuchunilhwan. 2. The rate of feeding effect was not significantly decreased after oral administration of Hyungbangdojucksan-Gami and Kamsuchunilhwan. 3. After oral administration of Hyungbangdojucksan-Gami, the quantities of total cholesterol, HDL cholesterol, LDL cholesterol and triglyceride on the serum were significantly decreased but that of lipid peroxide on the serum was significantly increased. 4. After oral administration of Kamsuchunilhwan., the quantities of glucose, total cholesterol, LDL cholesterol and triglyceride on the serum were significantly decreased but those of HDL cholesterol, lipid peroxide on the serum were significantly increased. 4.Conclusion Hyungbangdojucksan-Gami and Kamsuchunilhwan have significant effects on the obesity in the rats.