Abstract： Objective To observe the clinical effects of BTX-A on the period of onset of migraine.Methods Sixty patients with migraine attacks were randomly divided into treatment group(C)and control group (M).Patients in control group(M)were given nimodipine tablets,and patients in treatment group were given BTX-A.changes of clinical effect were observed after 30 days.Results Total effeclive rates in control group and treatment group were 76.7% and 96.7%,respectively(P＜0.05).The pain onset time reduced and the numbers of the cases with the simultaneous phenomena of dizziness,tinnitus and foreign body sensation decreased significantly(P＜0.01).Conclusion BTX-A has a significant therapeutic effect on the period of onset of migraine.