Abstract: Female breast cancer has surpassed lung cancer as the most commonly diagnosed cancer in 2020. A large number of studies have proved that tumor infiltrating lymphocytes (TILs) are lethal to tumors and play an important role in identifying tumor antigens. Therefore, the application of TILs in clinical immunotherapy and prognosis assessment of breast cancer has attracted wide attention. In this review, the basic research progress and clinical application of TILs in different molecular types of breast cancer are reviewed, and the value of TILs in judging breast cancer prognosis and predicting the therapeutic effect of clinical immunotherapy is evaluated.