The purpose of this study was to investigate the effect of Monacolin-inoculated rice embryo on the body fat and serum lipid profiles in 61 obese elementary school students. The subjects divided into two groups 31 obese children had the experimental diet (rice embryo inoculated Monacolin) and 30 obese children had the control diet three times a day after meals. The mean age, height, weight, and BMI of 61 subjects were 10.5 +/- 0.5 years, 143.6 +/- 6.8 cm, 55.0 +/- 8.9 kg, and 26.1 +/- 3.9, respectively. The changes of body fat mass (kg) in experimental group and control group after 6 weeks were -0.60 kg and -0.03 kg, respectively. The changes of body fat (%) in experimental group and control group after 6 weeks were -1.44% and -0.25%, respectively. These changes of body fat in experimental group were significantly higher than in control group (p < 0.05). The change of total-cholesterol in experimental group and control group during 6 weeks were -17.52 mg/dL and -1.70 mg/dL, respectively. The change of LDL-cholesterol in experimental group and control group during 6 weeks were -17.06 mg/dL and -2.80 mg/dL, respectively. The change of triglyceride in experimental group and control group after 6 weeks were -9.58 mg/dL and 11.67 mg/dL. Total-cholesterol, LDL- cholesterol and triglyceride of experimental group after 6 weeks significantly decreased compared to control group (p < 0.05). After experimental diet (6 weeks), total-cholesterol was negatively correlated with body water contents, soft lean mass and fat free mass (p < 0.05). Triglyceride showed a significantly positive correlation with body weight and body fat mass, however, it was negatively correlated with fat free mass (p < 0.05). HDL-cholesterol showed a significantly positive correlation with fat free mass (p < 0.05). These results show that Monacolin-inoculated rice embryo is effective in decreasing body fat and blood lipid in obese children.