Abstract: Objective: To analyze the clinical manifestations, imaging features, and pathological characteristics of primary central nervous system lymphoma (PCNSL) and to explore the methods of diagnosis and treatment. Methods: The clinical, laboratory, imaging and pathological data from 31 cases with PCNSL seen in our hospital between July 1995 and June 2006 were retrospectively analyzed. Of the 31 cases, 18 received chemotherapy and radiotherapy after surgery, and 5 cases were treated with surgery alone. Results: PCNSL often appeared with nonspecific symptoms, such as elevated intracranial pressure and nerve dysfunction, leading to a relatively high misdiagnosis rate. All patients' CSF cellular examination was negative. All of the 31 cases were B- cell lymphoma. Twenty- four of the 31 cases were followed up for 6- 98 months. The mean survival was 20 months in the group that received surgery combined with chemotherapy and radiotherapy and 10 months in the group that underwent surgery alone. Conclusion: PCNSL has no specific clinical manifestations, thus it is difficult to diagnose. The pathological examination might be the only reliable method to confirm PCNSL. The main objective of surgical therapy is to lower the intracranial pressure. Recurrence may occur after surgery alone, so a combined therapy with additional radiotherapy and chemotherapy is needed to prolong patients' survival period.