This study was to investigate the effects of high-fat diet feeding for a very long period of time on gene expression of inflammatory cytokines in mouse adipose tissue and to determine whether caloric restriction (CR) or insulin sensitizer treatment changes the cytokine gene expressions even in obese mice fed a high-fat diet for a very long term-period. Gene expression levels of tumor necrosis factor-${alpha}$ (TNF-${alpha}$), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) were examined by real-time PCR in subcutaneous abdominal adipose tissue (SubQ) from obese and non-obese male C57BL/6 mice at 16, 26, 36, 47, and 77 weeks of age on either normal diet (ND) or high-fat diet (HFD) after starting at 6 weeks of age. In addition, gene expression levels of TNF-${alpha}$, IL-6 and MCP-1 were determined in SubQ before and after rosiglitazone treatment or CR on 47-week-old obese mice. The results demonstrated that gene expression levels of TNF-${alpha}$, IL-6 and MCP-1 were significantly increased with aging in SubQ of mice in both groups of diet. MCP-1 gene expression of SubQ in all ages tested was significantly or marginally increased in mice on HFD compared with ND. While TNF-${alpha}$ expression was significantly reduced by rosiglitazone, IL-6 and MCP-1 were significantly decreased by CR. The basic data in this study will be useful for characterizing the C57BL/6 mouse as an animal model of obesity induced by high-fat diet feeding for a very long period of time, and a better understanding of inflammatory cytokine regulation in diet induced obesity which may facilitate the development of new therapeutic strategies to prevent the complications of obesity.