Objective:To analyze the clinical efficacy and prognostic factors of intracranial primary diffuse large B-cell lymphoma (DLBCL).Methods:Clinical data of 205 patients pathologically diagnosed with intracranial primary DLBCL at Sun Yat-sen University Cancer center from March 2001 to September 2020 were retrospectively analyzed. Among them, 101 patients were male and 104 female, the median age was 54 years old. Non-germinal center B cell (GCB) subtype accounted for 74.1%(126/170). A total of 177 patients received high-dose methotrexate (HD-MTX) and 91 patients received rituximab. After induction chemotherapy, 59 patients (30.4%) achieved complete response (CR), 112 patients (57.7%) achieved partial response (PR) or stable disease (SD). A total of 83 patients received consolidation or salvage radiotherapy, and only 14 patients received autologous stem cell transplantation (ASCT). The influence of pathological type, chemotherapy, rituximab treatment, radiotherapy and radiotherapy mode, ASCT and other factors on the overall survival (OS) and progression free survival (PFS) was evaluated. The survival rate was calculated by Kaplan-Meier method. Univariate prognostic analysis was performed by log-rank test. Multivariate prognostic analysis was conducted by COX model.Results:The median follow-up time was 34 months. The 5-year OS and PFS rates were 55.6% and 44.2%, respectively. GCB subtype, chemotherapy with HD-MTX, rituximab treatment, remission status after induction chemotherapy, and radiotherapy were favorable prognostic factors for OS or PFS, in which the last three were the independent prognostic factors. Consolidation radiotherapy in patients who obtained CR after induction chemotherapy did not significantly improve survival, while salvage radiotherapy in patients who achieved PR/SD after induction chemotherapy significantly improved both OS and PFS(both P<0.01). Consolidation radiotherapy showed no significant survival difference compared with consolidation ASCT. Conclusions:The non-GCB subtype of intracranial primary DLBCL is related to poor prognosis. The addition of rituximab to HD-MTX based induction chemotherapy can improve survival. Radiotherapy is still an important treatment for intracranial primary DLBCL, and there are limitations of ASCT in practical clinical application.