目的　原发性中枢神经系统淋巴瘤很少见 ,本文报道 3例原发性中枢神经系统淋巴瘤 ,以提高人们对本病的认识。方法　回顾性分析 3例患者的临床资料。结果　 2例患者临床以半身无力为主要症状 ,头颅CT、MRI检查示占位性病变 ,其中 1例多发 ( 3个病灶 ) ,1例单发。分别经脑活检和手术病理证实为淋巴瘤。 1例患者首发症状为双侧视力障碍伴双下肢无力 ,经头颅CT、MRI检查未见异常 ,经脑脊液细胞学检查及免疫分型 ,诊断为淋巴细胞瘤。结论　中枢神经系统淋巴瘤 ,特别是侵犯脑膜而非脑实质时 ,影像学检查有时也很难确诊 ,脑脊液细胞学检查为这些患者提供了可靠的临床诊断方法。 Objective Primary central nervous system lymphoma is rare, this article reports 3 cases of primary central nervous system lymphoma, to raise awareness of the disease. Methods The clinical data of 3 patients were retrospectively analyzed. Results Two patients were clinically as the main symptom of hemiplegia. Head CT and MRI showed occupational lesions. Among them, 1 was multiple (3 lesions) and 1 was single. Respectively by brain biopsy and surgical pathology confirmed as lymphoma. The first symptom of one patient was bilateral visual impairment with weakness of both lower extremities. No abnormalities were detected by CT and MRI, and cytology and immunophenotyping of cerebrospinal fluid were used to diagnose lymphocytic tumors. Conclusions Imaging of the central nervous system lymphomas, especially those involving the meninges other than brain substantia nigra, is sometimes difficult to diagnose and cerebrospinal fluid cytology provides a reliable clinical diagnostic modality for these patients.