Infiltrated immune cells and cytokines in the tumor microenvironment may play different functions that appear tightly related to clinical outcomes.Radiotherapy mainly kills tumor cells through radiobio-logical effect,meanwhile it can indirectly change tumor immunologic microenvironment,and has a local or dis-tant anti-tumor immunological effect cooperatively.Animal experiments and clinical trials of radiotherapy com-bined with immunotherapy display well applied prospects,but the mode of radiotherapy in combined treatment needs further research.