The purpose of the present study was to investigate effects of kochujang and red pepper on energy intake, body fat content and energy expenditure in rats fed on high-fat(30%) diet. Kochujang and red pepper power were added in the high-fat diet, adjusting the level to 95 and 22g/kg diet, respectively, The level of red pepper addition was corresponding was corresponding to the level of the content of red pepper powder in the kichujang-added diet. Kochujang induced a 30% reduction in body fat gain which was associated with a significant increase in energy expenditure. However, red pepper reduced body fat gain by only 15%. Furthermore, energy expenditure was not affected by red pepper. Metabolizable energy intake, apparent digestibility and body protein gain were not affected by either kochujang or red pepper. It has been known that capsaicin, a pungent component of red pepper, enhances activity of brown adipose tissue through increasing protein content. In the present study, in addition of protein content, DNA content of interscapular brown adipose tissue was also increased by kochujang. Therefore, it appeared that the anti-obesity effects of kochujang was greater than those of red pepper, indicating more than red pepper was involved in the expression of the anti-obesity effects of kochujang(Korean J Nutrition 33(8) : 787-793, 2000)