Objective: To study alterations of perihematomal cerebral perfusion associated to subacute and chronic intracerebral hemorrhage (ICH) by means of computed tomography perfusion (CTP) imaging. Methods: Non-enhanced CT scan and CTP examination were performed in 12 patients with subacute and chronic supratentorial ICH. The hematoma volume was measured, and the regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), mean transit time (MTT) and time-to-peak (TTP) adjacent to hematoma were measured in 11 of 12 cases. Results: Eleven patients with mean age of 58.1 years were finally analysed. Mean time interval from symptom onset to initial CTP scanning was 18.4 days; mean hematoma volume was 26.8 ml. The gradient of hypoperfusion around the hematoma was revealed by rCBF maps in 11 cases, and by rCBV maps in ten cases. The areas of delayed TTP and MTT were showed in 11 and ten cases, respectively. The degree of reduction in rCBV correlated strongly with the hematoma volume (r(inner)=0.764, p=0.006; r(outer)=0.703, p=0.016). There was no correlation between the changes in rCBF, rCBV, MTT and TTP and the time interval from symptom onset to initial CTP examination. Conclusion: We have concluded that the gradient of hypoperfusion surrounding the hematoma may still exist during the subacute and chronic phases after ICH. The alterations in rCBV correlate with the hematoma volume. We believe that the reperfusion injury marked by increased rCBV contributes to the perilesional brain injury. The quantitative CT perfusion measurements can provide valuable information in individual management and prognostic evaluation of ICH.