Abstract: Objective :To discuss the value of application for the change of tumor markers in evaluation of the effect of chemotherapy on lung cancer. Methods :CYFRA21-1, CEA and NSE were tested by eletro -chemiluminescence immunoassay in the patients with lung cancer before and after chemotherapy. Results : The value of adenocarcinoma CEA, squamous cell carcinoma CYFRA21-1 and of small cell lung cancer NSE in the PR group were lower compared to that before chemotherapy (P<0.05). In the PD group with adenocarcinoma, the value of CEA increased (P<0.05). In the NC group, there was no significant difference before and after chemotherapy (P>0.05). Conclusions :Monitoring on the change of tumor marker CEA, CYFRA21-1 and NSE before and after chemotherapy will be beneficial for evaluation of the effect of chemotherapy on lung cancer.