Objective To study alterations of permeability of surface(PS)in subacute stage intracerebral hemorrhage(ICH)patients with computed tomography perfusion imaging(CTPI),and to investigate its correlative factors.Methods 26 consecutive patients with ICH admitted to the department of neurology of the No.1 affiliated hospital of Wenzhou Medical University from November 2015 to April 2016 were recruited in the study.All patients underwent CTPI at days 8±2 after symptom onset.The volume of the hematomas was calculated,and the perfusion parameter values were measured including cerebral blood flow(CBF),cerebral blood volume(CBV),mean transit time(MTT)and PS in the hematoma and 1cm-wide area around the hematoma.Also rCBF,rCBV,rMTT and rPS were calculated by ipsilateral/contralateral value.Results Compared with the mirror area,the CBF and CBV of the hematoma and perihematoma showed lower,the MTT was longer(P<0.05).There was statistically differenc between the PS in the core area of the hematoma(0.32±0.21 mL/100g/min)and PS in the contralateral regions(1.40±0.59 ml/100g/min; P=0.00).And perihematoma PS(1.65±0.46 mL/100g/min)was higher than PS in the mirror area(1.47±0.41mL/100g/min; P=0.001).rPS in the hematoma(0.25±0.19)was signally lower than that in the perihematoma(1.12±0.14; P=0.001).Perihematoma PS correlated positive with the perfusion parameter of MTT(r=0.414; P=0.035),it also correlated correlated negatively with CBF(r=-4.07,P=0.039).Wether perihematoma PS nor hematoma PS had the correlation with the hematoma volume.Conclusions In the subacute phase of ICH patients,perihematoma regions have suffered worse secondary brain injury,resulting in the the higher permeability with the opening of the blood–brain barrier(BBB)in a long period of time.Elevated permeability can be detectable in subacute stage by using CTPI.The quantitative analysis of the PS may be with certain clinical applicatin value in future.