As the obesity has been known to be related with the hyperlipidemia, cardiovascular disease, cerebral apoplexy, fatty liver, and other chronic diseases, recent researches have focused on the functional food materials and their anti-obesity activities. This study was performed to study the effects of vanilloid family capsaicin, major pungent ingredient of hot chillies and peppers, on anti-obesity activities. ICR male mice were fed one of the pellet diet, basal diet, and high fat diet with capsaicin (45 $mu extrm{g}$/day) solution for 5 days. Mice in the corresponding control groups were given water for 5 days. In results, capsaicin reduced body weights in any diet groups. Percent weight and cell size of the abdominal white adipose tissue in mice on the high fat diet with capcaicin were significantly lower compared with those in mice on the high fat diet with water. However, percent brown adipose tissue weight per body weight in mice on the high fat diet was not affected by capsaicin. Capsaicin reduced the levels of s-triglyceride and s-total cholesterol in the pellet diet or high fat diet groups. There was no difference in the s-protein levels between the capsaicin group and the control water group. These data indicate that 1) orally administered capsaicin has a reducing effect on the blood triglyceride and total cholesterol levels, and 2) capsaicin has lowering effects on the body weight, percent weight and cell size of the abdominal white adipose tissue.