Objective To study the effect of external counterpulsation on cerebral blood flow. Methods Cerebral blood flows were simulated on hemodynamics models of cerebral blood on condition of normal and stroke with practical measured normal carotid blood pressure pre-ECP and during ECP. Results stroke and ECP may bring change of blood perfusion flow of brain. Conclusion the blood perfusion of brain was improved and the time-dependent pattern of timedependent cerebral arterial blood was changed with ECP.