OBJECTIVE: To propose a method for diagnosis and differential diagnosis of myasthenia gravis (MG) with heart and liver injury, anisocoria, dysacusis, impatience etc. METHODS: (1) Before and after administering cholinesterase inhibitor and immune therapy, 55 patients with MG were re-examined for heart and liver and followed up. (2) 1 mg neostigmine was injected to the MG patients with anisocoria and dysacusis, the symptoms were observed and brainstem auditory evoked potential was performed before and after 30 minutes and 2 hours. RESULTS: With the relaxation of muscular weakness and fatigability distinctive of MG, other special symptoms will improve and no further special therapy is needed. CONCLUSIONS: MG is an autoimmune disease mediated by auto-antibodies that attack the acetylcholine receptors not only at the skeletal muscle, but also at many other organs such as heart, liver, hearing apparatus pupillary sphincters and genitals. With the relaxation of muscular weakness, these symptoms will improve. The effect of administering cholinesterase inhibitors is the key point of differential diagnosis.