Aim To study the cerebral hemodynamics and influencing factor by using multislice CT perfusion imaging in early acute cerebral infarction. Methods Seventeen patients doubted with cerebral infarction by routine CT scan with negative results underwent CTPI and CTA within 6 hours. CTPI with cerebral blood flow(CBF),cerebral blood volume(CBV) and time to peak(TTP) were observed and evaluated.All cases were followed-up with CT or MRI after 2 to 7 days. Results The CBF,CBV at gray and white matter in ischemic region were lower than that in opposite side in early acute cerebral infarction patients(P<0.05).The CBF at gray matter in opposite side in patients was lower than that in control group,the CBV,TTP at gray matter and CBF,TTP at white matter in opposite side in patients were higher than that in control group(P<0.05).The age of patients and the cerebral hemodynamics was correlated in early acute cerebral infarction patients(CBF r=-0.707,CBV r=-0.658) (P<0.05). Conclusion The cerebral hemodynamics were changed not only in ischemic region but also in opposite side in early acute cerebral infarction patients.The age of patients acts as an importment influencing factor in ischemic region in early acute cerebral infarction patients.