Abstract： Objective To evaluate the role of perfusion weighted magnetic resonance imaging ( PWMRI ) in distinguishing brain glioma recurrence for postoperative radiotherapy patients.Methods Thirty-five patients with suggested recurrent brain glioma (20 true,15 false) were examined by conventional MRI and PWMRI.Regions of interests (ROI) were manually drawn in contrast-enhancing lesion,surround edema region and normal white matter of contra-lateral brain on regional cerebral blood volume (rCBV) images.rCBV values of ROI and rCBVmax were measured,the standardized rCBV ratios were calculated,The mean rCBVmax ratio were compared between two lesion types with group t-test.The rCBVmax ratios of contrastenhancing regions was analyzed by the receiver operating characteristic curve.Results The mean rCBVmax ratio of contrast-enhancing lesion in tumor recurrence was higher than those in non tumor recurrence (4.36vs 1.28,t =3.00,P =0.005 ).The mean rCBVmax of edema regions in tumor recurrence was also higher than those in non tumor recurrence ( 1.79 vs 0.85,t =2.41,P =0.026).Four patients with recurrent tumor and three with non tumor recurrence were wrong diagnosed when set the recurrent tumor rCBVmax ratio ＞2.15.The diagnostic sensitivity,specificity and accuracy for recurrent tumor by PWMRI were 80％respectively.Conclusion PWMRI examination is a useful method for distinguishing brain glioma recurrence.