Abstract: Objective: To investigate the changes of brainstem auditory evoked potential( BAEP) and its mechanisms in adult patients with migraine during attack. Methods: Sixty ineurs( migraine group) and fifty normal subjects( control group) were performed BAEP and transcranial Doppler examination. Results: The right Ⅲ and bilateral Ⅴ wave latencies,the left Ⅲ- Ⅴ,right Ⅰ- Ⅲ and bilateral Ⅰ- Ⅴwave interpeak latency of BAEP in the migraine group were significantly longer than those in the control group( P 0. 05- P 0. 01). The peak velocity and mean blood flow velocity of the bilateral vertebral artery,basilar artery and posterior cerebral artery of the migraine group were significantly slower than those of the control group( P 0. 01). Conclusions: Neurophysiological changes are observed in the right areas of the brainstem of migraine patients during attack; slow vertebrobasilar system blood flow might be relevant to the mechanism of the change.