Lung cancer is among the most prevalently occurring carcinomas worldwide, and reducing lung cancer mortality depends on early detection, diagnosis, and treatment. Given the rapid development of molecular biology and modern techniques for diagnosis and treatment, the study of serum tumor markers has gained extensive application in early diagnosis, treatment effect monitoring, and prognosis evaluation. Serum tumor markers possess the advantages of easy detection, noninvasive operation, and cost-effectiveness. This article reviews the progress in the study of serum tumor markers of lung cancer.