Abstract: Gestational diabetes Mellitus（GDM） is a clinical syndrome with abnormal expression of multiple genes and environmental factors，its incidence increased year by year，so explore the pathogenesis and pathophysiology of GDM is very important for the prediction and intervention. Pregnancy related insulin resistance exceeds the limits of compensatory β islet cell′s function is a recognized reason of GDM, however, the exact pathogenesis is not fully understood. In recent years, new studies have found that the immune and genetic factors play important roles in the occurrence and development of GDM. This article is from the view of immune and genetic，discuss the T cells, HLA complexes and other changes in patients with gestational diabetes，wishing to provide new ideas for further research of GDM′s pathogenesis.

Key words: Diabetes, gestational, Diabetes mellitus, type 2, Diabetes mellitus, type 1, HLA antigens