As a useful supplement for TNM staging system of non-small cell lung cancer (NSCLC),circulating tumor cell (CTC) can better reflect the comprehensive condition of the patient.CTC plays an important potential role in monitoring curative effect of lung cancer,and has the effect of real-time detection.With the development of the CTC detection method and the improvement of sensitivity and specificity,clinical studies about CTC will provide more help for prognosis evaluation.