1.Age less than 75 years old; 2.No impairment of consciousness, but still can be considered for thrombosis of the vertebrobasilar system; 3.Blood pressure less than 180 MMHG systolic or 110 MMHG diastolic before treatment; 4.Onset less than 4.5 hours; 5.CT to exclude cerebral hemorrhage; 6.Exclude TIA; 7.No hemorrhagic disease and bleeding quality; 8.Patient or family consent