Studies have shown that two-thirds of breast cancers are estrogen-dependent and can resolve after estrogen reduction. In 1973, Schwarsel first proposed that aromatase inhibitors can specifically cause target enzyme inactivation, block aromatization, inhibit estrogen production, and reduce estrogen levels in the blood to achieve breast cancer treatment. A series of compounds that inhibit AR activity. As a new idea for the treatment of breast cancer, aromatase inhibitors have attracted the attention of relevant scholars. After nearly 30 years of efforts, three generations of AR inhibitors have been developed and marketed as second- or third-line drugs for the treatment of breast cancer in the United States. , Japan, etc. have been widely used in clinical practice. AR inhibitors can be classified into steroids and non-steroids according to their structure.