Abstract： Objective To analyze the clinical characteristics and the prognostic factors of carcinomatous meningitis(CM). Methods 63 patients with CM treated in Tianjin Medical University Cancer Institute and Hospital from 1998 to 2008 were reviewed retrospectively. The correlations between clinical characteristics, treatment modalities and the prognosis of CM were analyzed. The common primary site was lung cancer(65%)and breast cancer(13%). All the patients were underwent MRI scan and 29 of the patients received lumbar puncture. Fifty-one patients received whole brain radiotherapy, systemic and/or intrathecal chemotherapy. The other 12 patients only received supportive care. Kaplan-Meier method and Log-rank test were used for survival analysis. Results All patients died by the end of follow-up. The follow-up rate was 95%. The number of patients who undergone 1-,2 years follow-up were 59 and 56. The median survival time was 2. 2 months(range :0. 1 -24. 4 months)for the entire group. The clinical stage and the control status of the primary disease were strongly correlated with survival(x2 = 6. 68, P = 0. 036)and(x2 = 7.04, P = 0. 008). The median survival time was 3.0 months(range: 1.0 - 24. 4 months)in patients who received ≥30 Gy whole brain irradiation, while only 1.8 months(range:0. 1-14. 2 months)in those who did not receive radiotherapy(x2 =5.54,P =0. 019). The median survival time of radiotherapy ± chemotherapy group, chemotherapy only group and supportive treatment only group were 3.0 months (range :0. 5 - 24. 4 months), 2. 2 months(range :0. 3 - 14. 2 months)and 1. 2 months(range :0. 1 - 4.5 months), respectively(x2 = 9. 32, P = 0. 009). Conclusions The prognosis of CM is very poor. The clinical stage before the diagnosis of CM and the control status of primary disease and were significantly correlated with survival. Sufficient whole brain irradiation dose may prolong survival and worth further study in a large sample study.