Recently, the prevalence of diabetes and metabolic syndrome is increasing and has become a social problem. Considering the fact that many Koreans consumed fermented milk, this study was performed to determine the positive effect of fermented milk with indigestible dextrin formulation (Dr. Insue) for patients impaired glucose tolerance or potentially metabolic syndrome, diabetic. Long-term drinking of fermented milk, Dr. Insue did not cause the rise in blood glucose after a meal and has no side effects such as discomfort digestive-organ in spite of intake 12 wk. Also, It confirmed that there is no adverse effect about hematological and biochemical tests, including glycosylated hemoglobin. It is suggested that fermented milk, Dr.Insue is suitable beverage for potentially diabetic patients with metabolic syndrome of impaired glucose tolerance. Additionally, it should be considered to be a means to investigate the changes of cardiovascular risk of ingestion of the fermented milk and research through the increases the amount indigestible dextrin formulation or extending the period of intake. Keywords: fermented