Abstract: Prostate cancer ranks first among adult males in the United States, and second in cancer-related mortality. Androgen deprivation therapy (ADT) is the most commonly used treatment for prostate cancer and is usually a lifelong treatment with the patient. Androgen and ADT have a profound impact on the immune system, and this finding is particularly important in the ear of current immunotherapy. Studies have shown that ADT may promote or inhibit immunotherapy. This article reviews the mechanism of action of different types of ADT drugs, discusses their effects on prostate cancer cells and immune system, and the prospect of combination of ADT and immunotherapy, to provide new thought and vision on the treatment of prostate cancer.