Aim To observe the effect of epimedium on the proliferation and stem cell-like character expression of breast cancer cells, and investigate the relationship between the inhibition of stem cell-like character and miR-148a by epimedium, and its molecular mechanism. Methods After treatment with different concentrations of epimedium, cell viability and population dependence were detected by MTT assay and colony formation assay; the breast cancer stem cell-derived mammosphere formation was examined by Mammosphere assay; the expression levels of CD44,ALDH-1, Oct4,BMIl and EpCAM were detected by qPCR; the protein expression levels of EpCAM, SOX4, ZO-1, E-cadherin and vimentin were detected by Western blot; the protein localization of EpCAM was observed by im-munofluorescence assay; the effect of epimedium on migration was detected by wound healing assay. The miR-148a mimic was transfected into MDA-MB-231 cells, and the effects of epimedium on stem-like character expression of transfected MDA-MB-231 cells were observed. Results Epimedium significantly inhibited the proliferation and population dependence of MDA-MB-231 cells (P < 0.05 ), and reduced the breast cancer stem cell-derived mammosphere formation; compared with control group, epimedium significantly decreased mRNA levels of CD44, ALDH-1, Oct4, BMI1 and EpCAM (P <0.05) ,decreased protein contents of EpCAM, SOX4 and Vimentin (P < 0.05 ), up-regulated the protein expression of ZO-1 and e-cadherin ( P <0.05) ,and decreased the migration ability of MDA-MB-231 cells (P < 0.05). Epimedium up-regulated the expression of miR-148a in MDA-MB-231 cells (P <0.01). YYH + miR-148a mimic group significantly inhibited stem-like character expression and EMT process of breast cancer MDA-MB-231 cells compared with control group (P <0.05). Conclusions Epimedium can inhibit the proliferation of MDA-MB-231 cells, which may be related to the up-regulation of miR-148a, decrease of stem-like character expression of breast cancer cells,and inhibition of EMT.