The aim of the present study was to assess the anti-obesity effects of fermented kochujang supplement in C57BL/6J mice. Thirty mice were divided into 3 groups; normal diet control group (ND), high fat diet control group (HD), and high fat diet plus kochujang supplemented group (HDK). Results were as follows: 1. Fennented kochujang supplement in high fat diet decreased body weight and epidydimal and back fat weight compared to non-supplement in HD group. 2. Lipid content and blood glucose level were lower in HDK group than HD group. 3. Fermented kochujang supplement increased mRNA level of lipolytic genes such as acyl-CoA synthetase (ACS), carnitine palmitoyltransferase-1 (CPT-1), and uncoupling proteins-1 (UCP-1) expression, whereas decreased mRNA level of adipogenic genes such as acetyl CoA carboxylase (ACC) expression. These findings suggest that fermented kochujang supplement in high fat diet normalized body weight, epididymal and back fat weight, lipid content, and blood glucose levels through controlling lipid metabolism and provides basic information on the control of obesity.