Abstract: Objective To study the clinical manifestations of multiple system atrophy. Methods Clinical diagnosis of syncope complicated by sphincter dysfunction in a pilot was analyzed and its related literature was reviewed. Results The patient was diagnosed as subtype Shy-Drager syndrome,a multiple system atrophy,according to vegetative nervous system failure,lesions of cerebellum and vertebral body.The patient also had manifestations of chronic respiratory failure,such as hypoxia,carbon dioxide retention and sleep-related respiratory disorder. Conclusion Early multiple system atrophy involves respiratory control center in brain stem,and therefore hypoxia,carbon dioxide retention and sleep-related respiratory disorders may occur in such patients.