Abstract： Objective To investigate the levels of erythrocyte immune adherent function, T lymphocyte subsets and their clinical senses in patients with gestational diabetes mellitus. Methods The erythrocyte immune adherent function and T lymphocyte subsets in 68 patients(observation group) with gestational diabetes mellitus were detected and compared with those of 50 normal subjects (control group). Results In observation versus control groups,the rate of erythrocyte C3b receptor rosette,CD3,CD4,CD4/CD8 were significantly lower (P<0.05),however, the rate of erythrocyte immune compound rosette,CD8 were significantly higher (P<0.05). Conclusions The erythrocyte immune adherent function in patients with gestational diabetes mellitus is damaged,which may affect T lymphocyte activation and inhibit the activation progress of T suppressor. Both of them have some correlation.