Breast cancer is one of the diseases with the highest mortality rate in the world and poses a serious threat to human and animal including pet heaths. MicroRNA(miRNA), as a small molecule of gene regulation, can mediate cellular target genes to regulate the occurrence and progression of breast cancer. In this paper, we classified miRNA according to their sources, reviewed the functional properties of endogenous and exogenous miRNA (botanmin), and pointed out their regulatory mechanisms for breast cancer. The potential targets of exogenous miRNA associated with breast cancer were predicted by bioinformatics, which provided a reference for the treatment of exogenous miRNA in breast cancer.