Abstract: Gestational diabetes mellitus (GDM) is clinically defined as cases with various degrees of impaired glucose tolerance or diabetes symptoms after pregnancy. GDM affects maternal and neonatal health. It will increase the risk of adult diabetes in a long run. The updated researches show that age, race, obesity, family history of diabetes, adverse reproductive history, hypertension, polycystic ovary syndrome, carriers of the hepatitis B virus (HBV) and α-thalassemia gene carriers are likely high risk factors of GDM. The global GDM epidemic ocurrence is increasing year by year. It is a comprehensive understanding of the risk factors for GDM and preventive screening for diagnosis as soon as possible. Diet, medication and other interventions will reduce the adverse health risks of GDM and their offsprings such as the probability of developing type 2 diabetes in GDM postpartum women and their offsprings.