Objective:To explore the correlation between dietary iron intake and gestational diabetes mellitus(GDM), and provide a reference for the prevention of GDM. Methods:Totally 108 cases of GDM in prenatal women were selected according to OGTT (75 g glucose tolerance test)as GDM group, randomly selected 108 cases of pregnant women with normal glucose tolerance as the control group. Case-control analysis was carried out between the two groups. Through questionnaire survey, dietary survey and detection of iron overload level, the dietary iron intake and iron overload index were compared between the two groups. The OR values between GDM and its risk factors were analyzed by using multi-factor regression analysis. Results:The dietary iron intake in GDM was significantly higher than that in the control group(P < 0.01). The mean serum ferritin in GDM was (84.64 ± 68.19)-滋g/L, which was higher than the value of normal group(57.87 ± 55.77)-滋g/L(P = 0.002). The OR value of high dietary iron intake and risk of GDM was 1.037(95% confidence interval was 1.007~1.069). Conclusion:The high level of dietary iron intake is positively correlated with GDM.