Breast cancer is the most common malignant tumor that threatens women's health worldwide.The current clinical treatment methods of breast cancer cannot completely prevent the recurrence and metastasis of breast cancer，and even often cause many adverse reactions in patients，such as cardiovascular injury，low immunity，reduced drug sensitivity，and increased risk of postmenopausal diseases.Screening safe and efficient natural anti-breast cancer active ingredients，clarifying their anti-cancer molecular mechanisms，and developing new anti-breast cancer drugs are effective strategies for clinical treatment of breast cancer and improving the prognosis of breast cancer patients.Bioactive polysaccharide is one of the main sources of natural antitumor drugs.It has become a research hotspot for its pharmacological activity characteristics，such as low toxic and side effects，easy to be absorbed and utilized by the body，and synergistic effect with chemotherapy drugs.A variety of bioactive polysaccharides with anti-breast cancer effects have been found，but due to the complex structure of these polysaccharides，the anti-cancer mechanism of polysaccharides is not completely clear.This paper compiled bioactive polysaccharide anti breast cancer research literatures in recent years，and summarized from the biological characteristics of polysaccharide，the structure-activity relationship of antitumor activity of polysaccharides，and direct and indirect effect of breast cancer resistance mechanism of polysaccharide，so as to provide new scientific reference for clinical targeted therapy of breast cancer and anti-cancer drug research and development.