Abstract: Objective: To explore the clinical features and cytological changes of cerebrospinal fluid(CSF) in meningeal carcinomatasis.Methods: The clinical features and cytological changes of CSF of two meningeal carcinomatasis patients were analyzed,and the literature was reviewed.Results: Of the two cases of meningeal carcinomatasis,one was due to acute change of chronic myelocytic leukemia and the other had received surgery for breast cancer.The main clinical manifestations were headache and vomiting.No spinal nervous lesion or signs of meningeal irritation were observed.Abnormal level of intracranial pressure,increased cell count and protein level were found in CSF examination.Cancer cells were found in cytological examination Conclusions: The cytological examination of CSF is essential for the diagnosis of meningeal carcinomatasis.