Abstract： Breast cancer(BC)is one of the most common malignancies and has the highest mortality rate among female pa-tients.The high mortality rate in BC patients is associated with recurrence and metastases to distal organs such as bone,lung,brain and liver.The signaling pathways involved in the development of brain metastases of breast cancer are known to be the PI3K/Akt/mTOR,Wnt/β-catenin,RAS/ERK,EGFR,STAT3,ROS/NF-κB and PDGFB/PDGFR-β pathways.In addition,it has been found that exosomes,non-coding RNAs and metabolic components can be involved in the brain metastasis of breast cancer by disrupting the blood-brain barrier and assisting the establishment of the brain metastasis microenvironment.In this paper,we review the signaling pathways and molecular mechanisms associated with brain metastasis in breast cancer,and hope to provide new ideas for the targeted treatment of this disease.