Objective To study the impacts of Mycophenolate Mofetil (MMF) combined with immune globulin on CD4+T cell subsets and cytokines in patients with myasthenia gravis (MG).Methods A total of 76 patients with MG were selected and randomly divided into a control group and a combination group (n=38,respectively).The control group was treated with MMF and the combination group with MMF+immune globulin for six months.The effects between the two groups were compared.Results The overall response rate (ORR) in the combination group was 94.74%,which was significantly higher than that in the control group,which was 78.95% (P < 0.05);after the treatment,the muscle weakness severity score (MWSS) and MG activities of daily living (MG-ADL) scores in the two groups decreased significantly,the CD4+CD25+,CD4+CD25+Foxp3+,and CD4+IFN-γ+ cell percentage of peripheral blood (PB) increased greatly,and CD4+Th17+ cell percentage decreased greatly;the levels of interleukin 2 and 7 (IL-2 and IL-17) decreased significantly,the levels of IL-4 and IL-10 increased greatly,and the decrease in the combination group was greater than the increase in the control group (P < 0.05).No adverse reactions occurred in the two groups.Conclusion MMF combined with immune globulin has significant effects in the treatment of MG,can dramatically improve the muscle weakness severity,quality of life and immune dysfunction in patients,and is safe and effective.