Objective:To preliminarily evaluate the feasibility and potential values of whole-brain perfusion imaging performed with 256-slice CT to assess normal adult cerebral hemodynamics. Methods: Thirty-five normal results were selected from one hundred and fourteen patients who underwent brain CT unenhanced scan,CT perfusion imaging and CT angiography in head and neck for suspicion of ischemic cerebrovascular disease. The radiation dosage of CT perfusion imaging was recorded. Two senior neuroradiologic doctors independently analyzed the CT perfusion maps. Region of interest(ROI) was placed on bilateral temporal gray matter of two slices(the basal ganglia slice and body of lateral cerebral ventricle slice) supplied by middle cerebral artery,and the cerebral blood flow(CBF),cerebral blood volume(CBV),mean transiting time(MTT) and time to peak(TTP) values of ROI were automatically calculated by CT perfusion software. The mean values of perfusion parameters were compared by one-way ANOVA test. Results: The radiation dosage of thirty-five normal adults was 2.307 ± 0.008 mSv. There were no statistically significant differences between the two observers on the mean values of perfusion parameters(P > 0.05). The CBV and CBF values of the two observers between two slices had statistically differences(P < 0.05). Conclusion: With the lower radiation dosage and the stable and reproducible perfusion parameters,whole-brain perfusion imaging performed with 256-slice CT can be used to assess the entire cerebral hemodynamics.