A case of Myasthenia Gravis, 24-year-old Korean male soldier with the complaints of speech and swallowing difficulty and difficult eyelid movements for 3 months. Physical examination revealed diminished gag reflex and inability of eyelids to close powerfully, and laborating findings were within normal limits except Ascaris lumb. The patient had remarkable response to Neostigmine I.V. injection and administered orally. No definite etiological cause was suspected such as thymus disorder and thyroid disease, but it is generally believed to be a noninherited, nonfamilial and autoimmune disorder.