Objective to investigate the diagnostic value of single and combined detection of tumor markers in serum and cerebrospinal fluid in patients with meningeal metastasis of lung cancer. Methods the expressions of alpha fetoprotein (AFP), human chorionic gonadotropin (HCG), carcinoembryonic antigen (CEA), neuron specific enolase (NSE), squamous cell carcinoma antigen (SCC), carbohydrate antigen 199 (CA199) and CA153 in serum and cerebrospinal fluid of 66 patients with meningeal metastasis of lung cancer (case group) and 66 patients with brain metastasis of non lung cancer (control group) were detected by chemiluminescence method. Results in the case group, 98.0% (65/66) were adenocarcinoma. The pos. rates of AFP, CEA, HCG, CA199, CA153, NSE and SCC in the serum of the case group were 0.0%, 83.0%, 0.0%, 3.0%, 6.1%, 4.6% and 4.6% resp., and those in the control group were 3.0%, 9.1%, 7.6%, 3.0%, 4.6%, 4.6% and 0.0% resp.; The pos. rates of AFP, CEA and HCG in cerebrospinal fluid of the case group were 0.0%, 75.0% and 0.0% resp., and those of the control group were 3.0%, 3.0% and 10.6% resp. The results showed that the pos. rates of CEA in serum and cerebrospinal fluid of the case group were significantly higher than those of the control group (P<0.05). The pos. rates of HCG in serum and cerebrospinal fluid in the control group were significantly higher than those in the case group (P<0.05). The pos. rate of CEA in serum and cerebrospinal fluid (95.5%) was significantly higher than that in serum and cerebrospinal fluid (83.0% and 75.8%, resp.) (P<0.05). Conclusion CEA has high specificity and sensitivity in the cytol. diagnosis of lung cancer meningeal metastasis. CEA combined with HCG can be used as an index for the differential diagnosis of lung cancer meningeal metastasis. Simultaneous detection of CEA in serum and cerebrospinal fluid will help to improve the pos. rate and differential ability of diagnosis.