Abstract: The incidence of cancer has been increasing in recent years, and has become a public health problem in the world. A tumor marker is a biomarker abnormally elevated in the blood, urine, or body tissues of cancer patients, which is typically produced by cancer tissues and can be used to indicate the appearance, development, prognosis of cancer, and the response to therapy, including radiotherapy. This review summarizes the potential role of serum tumor markers in predication of radiotherapy efficiency.