Purpose: The aim of this study was to explore the correlation between vitamin D receptor ApaI gene polymorphism and Gestational Diabetes Mellitus (GDM). Methods: 240 patients were divided them into GDM and non-GDM groups. DNA sampling was purified from peripheral blood and analysed by the PCR-RFLP for ApaI gene. BMI, Fasting Blood Glucose (FBG), and 1 h and 2 h Postprandial Glucose (PPG) were compared. Results: The genotype frequency of vitamin D receptor ApaI gene polymorphism significantly differed between two groups. Compared with AA genotype patients, the risk of gestational diabetes mellitus was significantly increased in those with CC genotype. Logistic regression analysis showed that there was no significant correlation between ApaI C allele and GDM. Conclusions: There was a significant correlation between vitamin D receptor ApaI gene polymorphism and GDM among pregnant women.