A total of1415 elderly individuals in Nanchang were included in the study and were divided into normal glucose tolerance group, impaired glucose regulation group, and diabetes mellitus group.The results showed that HbA1C was significantly correlated with fasting plasma glucose (FPG) and 2 h postprandial plasma glucose.When HbA1C 6.3% was applied as the cut point of diabetes, the sensitivity was 85.19% and the specifity was 99.45%.When HbA1C 6.5% was applied, the sensitivity was 75.56% and specifity was 99.61%.It seems that HbA1C 6.3% had higher specifity and sensitivity for diagnosing diabetes than HbA1C 6.5% and FPG 7.0mmol/L in studied population.