Abstract: Objective To investigate the diagnostic value of human epididymis protein 4(HE4) in lung cancer. Methods Serum HE4 level and carcinoembryonic antigen(CEA) level were measured in serum samples from 86 patients with lung cancer and 76 healthy controls using enzyme-linked immunosorbent assay(ELISA) and with electrochemical luminescence instrument and related reagents. Receiver operating characteristic(ROC) curve of HE4 and CEA for differentiation between lung cancer and healthy controls was drawn with the pathological diagnosis as the golden standard. At last,to explore the diagnostic value of HE4 combined with CEA. Results It proved that serum HE4 levels were significantly higher in lung cancer group[(257. 93 ±40. 51) pmol/L]than in control group[(257. 93 ±40. 51) pmol/L]. No significant difference was observed between stage Ⅰ- Ⅲ group[(251. 68 ±38. 59) pmol/L] and stage Ⅳ group[(268. 49 ±40. 66) pmol/L,P=0. 60)]. No significant difference was observed among Different pathological type of lung cancer(lung adenocarcinoma group:(261. 37 ±261. 37) pmol/L,lung squamous carcinoma group:(257. 42 ±257. 42) pmol/L,undifferentiated carcinoma of the lung group:(259. 75 ±28. 13) pmol/L,small cell lung cancer group:(266. 54 ±266. 54) pmol/L. The areas under the receiver operating characteristic(ROC) curve of serum HE4/CEA was 0. 908/0. 839. And the sensitivity of HE4 combined with CEA was 79. 1% which was larger than CEA(57. 9%) or HE4(73. 3%) alone. The specificity of HE4 combined with CEA was 85. 5%. For HE4,the specificity was 90. 8% and for CEA it was 86. 7%. Conclusion HE4 could be a potential diagnostic marker for lung cancer patients and has certain clinical value in the diagnosis of lung cancer.