Glycosylated hemoglobin(G-Hb) measurements were performed in normal adults and adult-onset diabetics, and G-Hb values were compared by age, sex, duration of diabetes mellitus, complications of diabetes mellitus, and types of therapy. Mean value of G-Hb was 5.0±0.92% in normal control and 7.9±2.50% in diabetes mellitus. In diabetics, G-Hb values with blood glucose level at the time of G-Hb measurement and blood glucose level 2~3 weeks before G-Hb measurement were compared. No significant correlation was observed between blood glucose levels and G-Hb. No significant correlation between G-Hb value and sex, age, duration of diabetes mellitus, complications of diabetes mellitus and types of therapy.