Abstract: The pharmacological effects of (-)-epigallocatechin-3-gallate (EGCG) on BCSCs were investigated in 3D culture system. The transcription level of epithelial-mesenchymal transition (EMT) associated genes were significantly downregulated by EGCG, resulting in the inhibition of BCSC migration including the reduction of cell number through 80 μmol/L pore and the attenuation of scratch repair capacity. In addition, the self-renewal capabilities including the expression level of stem cell marker genes and the clone formation capacity were also inhibited in cells cultured in 3D by EGCG. The proportion of stem cell population as detected by flow cytometry with CD24^-/low phenotype was also reduced by 80 μmol/L EGCG. Overall, the migration and self-renewal properties of BCSCs were significantly inhibited by EGCG in cancer cells cultured in 3D.