Abstract： Objective To investigate the incidence of glucose metabolism disorder during pregnancy and establish the diagnosis criteria for gestational diabetes mellitus (GDM) among Chinese patients.Method A prospective popolation-bused study of 16 286 pregnant women,who received 50 g glucose challenge test (GCT) for the first time between Apr 1,2006 and Sept 30,2006,was performed throughout 18 cities in China. Results According to national diabetes data group (NDDG)criteria,the overall incidence of GDM and glucose impaired glucose tolerance (GIGT) was 2.763% (450/16 286) and 3.862% (629/16 286),respectively; it changed to 5.078% (827/16 286)and 5.268% (858/16 286) when using American diabetes association (ADA) criteria.If the women who had 2 or more abnormal oral glucose tolerance test (OGTT) values meeting or exceeding ADA criteria was classified as group 1,and the women who had one or more meeting or exceeding NDDG criteria was group 2,the ratio of women who met both the criteria of ADA and NDDG in group 1 was 94.2%.The 95% CI of normal glucose when using ADA criteria were fasting glucose 5.3 mmol/L,1 hour 10.4 mmol/L,2 hour 8.7 mmol/L,3 hour 7.7 mmol/L,which is close to ADA criteria.Conclusions ADA criterion is more suitable for Chinese patients.According to NDDG criteria,it is reasonable to treat the patient with 1 or more abnormal OGTT values,and if choosing ADA criteria,2 or more abnormal OGrIT values is more reasonable.