Abstract: Objective To explore clinical characteristics and misdiagnosis of lung cancer with digestive tract symptoms as first manifestation in order to improve the awareness of the disease. Methods Fifteen primary lung cancer patients with digestive tract symptoms as first manifestation from January 2005 to January 2013 were enrolled，then their clinical data were analyzed retrospectively. Results The first clinical manifestations of 15 primary lung cancer patients included nausea and vomiting（7 cases），anorexia and weight lose（3 cases），eating choking（2 cases），abdominal pain（2 cases），and diarrhea（1 case）.There were 9 patients with refractoriness hyponatremia. There were 7 misdiagnosis cases of acute gastritis，3 of chronic gastritis，2 of esophagitis，1 of peptic ulcer，1 of cholelithiasis and 1 of acute enteritis.Eight patients were diagnosed as small cell lung cancer，including 7 cases with syndrome of inappropriate antidiuretic hormone secretion（SIADH）and 1 case with carcinoid syndrome. Two patients were diagnosed as lung squamous cell carcinoma with mediastinal lymph node metastasis. There were 5 patients diagnosed as lung adenocarcinoma，including 2 cases with supraclavicular lymphnode metastasis，2 cases with SIADH and 1 case with brain metastasis. Conclusion Lung cancer with digestive track symptoms as first manifestation is easily misdiagnosed. Clinicians should improve the awareness of primary lung cancer with digestive tract symptoms as first manifestation， and pay more attention to examination and diagnosis.