Abstract: Primary central nervous system lymphoma (PCNSL) is a rare extranodal lymphoma. Its pathological type mainly includes dif-fuse large B cell lymphoma. In MRI images, the condition is usually manifested as solitary deep lesions in brain parenchyma, with vari -ous forms of reinforcement. To date, chemotherapy based on high-dose methotrexate administration is the first-line therapy of PCNSL. Combined radiotherapy and chemotherapy can prolong the overall survival of patients. However, this approach simultaneously causes higher incidence of neurotoxicity. High-dose chemotherapy followed by autologous stem cell transplantation is recommended for re-current and refractory PCNSL. Temozolomide and rituximab can be used as treatment options because of their low toxicity and good tolerance. The prognosis of PCNSL depends on several factors, such as serum LDH concentration, age, ECOG /KPS score、cerebro-spi -nal fluid (CSF) protein concentration and tumor location.