Abstract: The granulocyte-macrophage colony-stimulating factor (GM-CSF) can effectively induce the proliferation of tumor-associated immunocytes as a hematopoietic factor; therefore, the fact that GM-CSF can induce systemic antitumor immune responses has attracted much attention. Radiotherapy, as one of the main treatment approaches of cancer, can kill tumor cells directly, and has an effect on anti-tumor immunity. Several clinical studies have shown that radiotherapy combined with the GM-CSF can induce an abscopal effect and confer favorable therapeutic effects for cancer. Herein, we review the research progress on GM-CSF, and radiotherapy combined with GM-CSF in tumor treatment.