According to the differentiation of symptamcomplex theory of Spleen Deficiency on myasthenia grvis, with our clinical experience of treatment for some years. Astragalus Saponins and Buzhong Yiqi compound were selected to make phannaceutic experiment for peripheral blood mononuclear cells culture of 14 samples of 10 myasthenia gravis patients. Two controlled groups were given with the treatment of dexamethasone and 60Co respectively. The results showed that liters of nAchR-Ab in cells culture superatants were significantly decreased by watersoluble Astragalus saponias (418.8-2328 fmol/rnl- 0 fmol/ml in 6 cases; 1143 -1235 fmol/ml - 43-157 fmol/ml in 2 cases). Buzhong Yiqi compund could enhance the immunoregulatory action.