Abstract: Blood ANP (atrial natriuetic peptide production). gastrin, CEA(carcinoembryonic antigen) were determinded in 75 patients with lung cancer,32 patients with benign lung disease and 32 normal individuals, 20 cases of 75 patients with lung cancer were compared the .variaty of each marker before and after treatment. The result showed that the mean of blood ANP. gastrin. CEA in patients with lung cancer was remarkably higher than in the controls (P＜0.01 ). The level of blood gastrin and CEA in the advanced lung cancer patients was higher significantly than inthe limited lung cancer. The mean of ANP and gastrin in sclc was much higher thanin squamous cell carcinoma and adenocarcinoma (P＜0.01 ). The mean of CEA inpatients with adenocarcinoma was higher than those with SCLC and squamous cellcarcinoma (P＜0.01 ). When CEA and gastrin were determined simultaneously thediagnotic value was increased. The mean of ANP, gastrin. and CEA in patientswith lung cancer decreased remarkably after chemotherapy and radiotherapy (P＜0.01). It is concluded that the determination of blood ANP. gastrin and CEA ishelpful in diagnosis, histologic classification and monitoring the response to therapyin patients with lung cancer.