OBJECTIVE To investigate the images characteristics of primary malignant intracranial lymphoma.METHODS Retrospective study was conducted on CT/MRI imaging characteristics of 9 cases with primary malignant intracranial lymphoma.RESULTS The patients had lesions mostly in the supratentorial region, including the parts of deep white matter, para-ependymal regions, and corpus callosum. The shapes of the lesions were round or irregular. CT scan showed equal or slightly high density of the tumor images, compared with the normal tissue in the brain.The TIWI of MRI scan on the tumor showed low signal and the T2WI showed equal or slightly high signal. The MRI signals were homogenous. Cystic lesion, calcification, and hemorrhage were rarely seen in MRI. Edema around tumor and its occupational effect was lessened. Edema around tumor shown in MRI was not in accordance with the true volume of the tumor mass. Enhanced scan on the lesions showed homogenous enhancement, and the pia mater invaded and/or the spread along ependyma. CONCLUSION Images of primary malignant intracranial lymphoma have specific characteristics that are useful in its diagnosis and differential diagnosis.