This study aims to promote the rational use of liquid biopsy in the clinical detection of lung cancer. Lung cancer is a malignant tumor with high morbidity and mortality worldwide. The incidence of lung cancer in China is expected to increase in the next few years with the aging population and environmental pollution. Early diagnosis and effective intervention are necessary in the clinical treatment of lung cancer. Surgical resection could achieve a better prognosis for patients with early lung cancer. However, for advanced lung cancer, individualized treatment based on the pathological classification, molecular genetic characteristics, and body conditions of patients could effectively prolong the lifetime. The prevention, diagnosis, and intervention strategies for lung cancer depend on the oncology information of patients. The techniques and methods used for detecting lung cancer in clinic include imaging technology, pathological biopsy, screening of blood tumor markers, and liquid biopsy technology, which has been developed recently. The liquid biopsy can capture the oncology information, including tumor load, tumor gene mutation, and so on, from the blood of patients with cancer by detecting circulating tumor cells, tumor exosome, circulating tumor DNA, and circulating tumor RNA. Moreover, it has become an important direction for clinical tumor detection because of its noninvasiveness, convenient sampling, and potential for overcoming tumor heterogeneity. This study intends to include 1000-2000 patients with stages I-IV lung cancer to research on lung cancer diagnosis, drug efficacy, surgical effect evaluation, recurrence monitoring, prognosis judgment, medication guidance, and molecular classification differentiation through the dynamic detection of blood ctDNA using the second-generation sequencing technology. The study also intends to analyze and establish the database with a large sample size.