Extracellular vesicle microRNAs(miRNAs) are a family of 19–25 nucleotides in length endogenous noncoding RNAs that can exert pleiotropic biological functions, prominently modulating their target genes expression at post-transcriptional level, affecting cell proliferation and apoptosis. Nowadays, for the biomarker of breast cancer, CA125, CA153, CEA, ER, PR, Her2/neu, and BRCA1/BRCA2 are increasingly unable to meet the clinical needs. Th erefore, new biomarkers are urgently needed for early diagnosis, treatment and prognosis of breast cancer. Extracellular vesicle miRNA plays a vital role in tumor development, invasion and metastasis, proliferation and apoptosis, and angiogenesis, etc. As a result, the identification and detection of specific miRNA can provide an excellent opportunity for patients with early stage breast cancer diagnosis and for alleviating disease burden.