Objective: The present study was done to examine the effect of dietary supplement containing Kurozu concentrate on human visceral fat accumulation. Material and Methods: Sixteen subjects(BMI≧25) were orally administrated Kurozu concentrate for 8 weeks(low dose group: 500 mg/day, high dose group 1000 mg/day). Before and at weeks 8, hematological analysis, urinalysis and CT-scan to estimate the visceral fat accumulation were conducted. Results: In high dose group, following results were obtained; visceral fat decreased significantly(p=0.033), HDL-cholesterol level elevated significantly (p=0.034) and systolic blood pressure decreased significantly(p=0.004). In addition, no serious symptoms or abnormal hematological values were observed in both group.Conclusions: The dietary supplement containing Kurozu concentrate may be useful to prevent a metabolic syndrome.