Diagnostic criteria in diabetes mellitus has been revised after 11 years. In addition to previous diagnostic criteria, HbAlc was added to the new criteria as a biomarker of chronic diabetes. Although NGSP >6.5 has become a marker of diabetes, the equation of HbA1c (NGSP) = 1.02 x HbA1c (JDS) + 0.25% was reported by analysis of global standardization. According to this equation, HbA1c (NGSP) 6.5% corresponded to HbA1c (JDS) 6.1%. In this symposium, we presented the viewpoint of the Japanese Society of Diabetes Mellitus for standardization of HbAlc and the issue of using NGSP instead of JDS.