Abstract: Lung cancer has become one of the leading causes of death from cancer.The mortality and morbidity of lung cancer has been increasing for years in China.Therefore, early diagnosis and accurate clinical staging of lung cancer is critical for guiding the treatment of lung cancer and improving the survival rate of patients with lung cancer.At present, the diagnosis of lung cancer is mainly depends on imaging, such as CT, MRI, SPECT, PET, etc.Besides, the tumor-associated antigen, such as lung tumor-associated antigen, cytokeratin fragment antigen21-1, neuron-specific enolase and carcino embryonic antigen also plays an important role in the diagnosis of lung cancer.