Abstract: We provide a new preclinical pharmacodynamic evaluation method of cerebral thrombolytics using beagle dogs with acute thrombotic cerebrovascular occlusion. An intracranial large vessel occlusion animal model was generated by pushing an autologous thrombus to the left carotid artery under X-ray angiography. The experiments were approved by the Animal Care and Welfare Committee Institute of Materia Medica, China Academy of Medical Sciences (CAMS), Peking Union Medical College. According to the degrees of cerebral blood flow reperfusion, the new method has 0, Ⅰ, Ⅱ (Ⅱa and Ⅱb), Ⅲ levels. Respectively, 0 level represents no blood flow through the area of vascular occlusion; Ⅰ level has low perfusion; Ⅱa level is less than half the infusion; Ⅱb level is more than half perfusion; Ⅲ level is completely recanalization perfusion. Alteplase was used as a positive drug to verify the accuracy of the method. Our results suggest that 100% of dogs reached the level of grade I and below in the model group, while 83% reached the level of grade IIa and above in the alteplase group. Results of a rank sum test showed that alteplase significantly improved the reperfusion of occluded cerebral vessels. We propose a method to evaluate the efficacy of thrombolytic drugs on dogs with middle cerebral artery occlusion.