Abstract: Objective: To analyze MRI findings of primary brain lymphomas（PBL）in immunocompetent patients.Methods: MRI and 1H-MRS findings in 11 patients with pathologically proved BL,6 male and 5 female,with mean age at 52.5 years old,were analyzed retrospectively.Results: Seventeen lesions were identified in 11 patients.The MRI findings of PBL were as follows:hypo-or iso-intense on T₁-weighted images and iso-or slightly hypo-intense on T₂-weighted images,solitary or multiple lesions and well-defined;mild or moderate peritumoral edema,and characterized by flame-like edema;the enhancement was intense and homogeneous;the presence of incision sign and angular sign was more specific.Conclusions: The conventional MRI plays an important role in the diagnosis of PBL.