Abstract: As the cancer with the highest incidence in women worldwide, breast cancer has always been a big threat to the health of women around the world. Estrogen receptor(ER) signaling pathway plays an important role during the pathogenesis of breast cancer. As an important target for the treatment of breast cancer, ER has attracted many pharmaceutical companies to develop related drugs. In 2002, the first selective estrogen receptor down-regulators(SERDs) developed by AstraZeneca-fulvestrant was officially launched in the United States. By reducing ER levels, fulvestrant shows a full inhibition of ER signaling pathway and superior clinical effects to other endocrine drugs. This makes SERDs get more and more attention from pharmaceutical companies. However, the clinical application of fulvestrant bas been limited by intramuscular injection, leaving much room for the improvement of SERDs. This review introduces the development status of SERDs, so as to provide reference for further research and application.