Objective:To investigate the effects of different immunosuppressant therapy on the efficacy and immune function of patients with generalized myasthenia gravis(MG).Methods:Retrospective analysis of clinical data of 86 patients with systemic MG,they were divided into control group(n=42,thiopyurine+glucocorticoid)and observation group(n=44,tacrolimus+glucocorticoid)according to different treatment methods.Both groups were treated for 1 year.The clinical efficacy,immune function index[Anti-acetyl-choline receptor antibodies(AchR-Ab),serum immunoglobulin A(IgA),immunoglobulin G(IgG)and complement(C4)],muscle function[QMGS scale,myasthenia gravis composite scale(MGC)],daily living scale(ADL)and adverse reactions were compared be-tween the two groups.Results:The total clinical effective rate after treatment was 93.18%in the observation group and 92.86%in the control group,and there was no difference in comparison(P>0.05).After treatment 3 month and 1 year,the QMGS score,MGC score and AchR-Ab,C4 levels of the two groups were lower than those before treatment(P＜0.05),and the ADL score and IgA,IgG levels increased(P＜0.05).The QMGS score and MGC score of the observation group were lower than those of the control group(P＜0.05),and the ADL score was higher than those of the control group at3 months after treatment(P＜0.05).There was no signif-icant difference in the comparison of the remaining indicators(P>0.05).There was no statistically significant difference in the inci-dence of adverse reactions between the two groups(P>0.05).Conclusion:Both azathioprine and tacrolimus can effectively treat sys-temic MG,restore normal muscle activity,improve immune function,and have low adverse drug reactions,but tacrolimus can be effective faster in the short term,and can be reasonably selected according to the needs and specific conditions of patients.