Objective To investigate the application of computed tomography（CT） and magnetic resonance imaging （MRI） fuse images for determining the target region in postoperative glioma. Methods CT and MRI images were fused from 10 patients. The CTV of each patient was independently determined by an associate chief doctor and a resident based on CT and MRI images. The CTV contoured on CT （CTV_CT） and MRI （CTV_MRI） were measured，and composite volumes （CTV_CT+MRI） were calculating as the sum of CT-defined CTV and MRI-defined CTV. Differences between these volumes were compared. Results Volumes of CTV_CT+MRI were larger than the volumes of CTV_CT（P<0.05） determined by all doctors. Volumes of CTV_CT determined by associate chief doctors was larger than that（P<0.05） determined by resident doctors. Volumes of CTV_CT+MRIdid not differ significantly between associate chief doctors and residents（P>0.05）. Conclusions CT-MRI fusion images can significantly improve accuracy in radiation therapy after glioma surgery.The composite volume （CTV_CT+MRI） may be less dependent on physician experience.