Obesity is caused by imbalance of energy intake and expense. If energy intake is more than its expenditure, body does fat accumulation and affects body weight. It can be fetal disease although obesity is not disease in itself. Central regulatary system is affected by many neurotransmitters regulating .food intake in brain. Hypothalamus was known as one of food intake regulation in CNS. In order to investigate gene expression difference in hypothalamus by different nutrient, we used C57/BL6 control mouse and db-/db- mouse. They divided each of two group with mouse, and fed control diet and high-fat diet for 4 weeks. Each of control and high-fat diet contained 11.7% and 59.7% fat, respectively. Then we performed microarray assay with them. We compared among changed genes in hypothalamus region. In the results, we observed that increased genes were more than decreased genes. Although hypothalamus size of db-/db- mouse is smaller than that of C57/BL6, more genes were affected in db-/db- mouse. In this study, many genes are affected by nutrient in hypothalamus region.