Abstract: Estrogen receptor-positive breast cancer is the most common subtype, which is most commonly treated with endocrine therapy.In order to address the issues of drug resistance and intolerance in endocrine therapy, selective estrogen receptor degrader(SERD) has become a hotspot in the research. Several oral SERDs have been developed to improve the pharmacokinetic properties with positive results in several clinical studies. Besides, novel target protein degradation technologies have been adopted to improve the degradation efficiency of estrogen receptor, with new SERDs being developed through protein hydrolysis targeting chimera and molecular gel technologies. This article reviews the status of endocrine therapy and the progress in the development and clinical research of oral SERD and novel protein degradation drugs, in the hope of providing some reference for the improvement of the prognosis of breast cancer patients.