Abstract: A co-thrombus inducer, a mixture of ADP, thrombin and epinephrine, was injected into rat carotid artery to induce cerebral thrombosis. Evans blue was used as an indicator to reveal the blood brain barrier (BBB) permeability. The concentrations of the dye in both the infarct hemisphere and the control hemisphere were determined by spectrophotometry. The effect of cinnarizine on rabbit platelet aggregation was also studied. It was shown that cinnarizine at the dosage of 67 mg/kg and 34 mg/kg inhibited the experimental cerebral thrombosis and the AA and ADP induced platelet aggregation, respectively. These results seem to indicate that this simple model may be used as an effective method to screen anticerebrothrombotic drugs.