Abstract: Immunosenescence is the decline in the structure and function of the body's immune system that involves organs, cells, immune factors, and regulatory networks. Decreased immunity and immune clearance, caused by immunosenescence, are key contributors to tumorigenesis. This article begins by introducing the concept of immunosenescence and provides a comprehensive description of the relationship between immunosenescence and tumorigenesis. We also discuss the influence of the various components of the immune system on tumor incidence. Finally, the article provides ideas for immunosenescence intervention aimed at the prevention and treatment of cancer.