Abstract: To explore the mechanisms by which AKR1C3 induces tumor resistance, human breast cancer cell strain MCF-7/DOX resistant to doxorubicin, MCF-7/ AKR1C3 cells for overexpression of AKR1C3 and MCF-7/DOX-KD cells for knockdown of AKR1C3 in MCF-7/DOX cells were established. Western blot analysis found that AKR1C3 was expressed at a higher level in MCF-7/DOX than MCF-7 wild type cells. Similarly, CCK-8 and DAPI confirmed that MCF-7/ AKR1C3 cells were more resistant to DOX than AKR1C3 wild types as the IC₅₀ was increased 6 times in MCF-7/AKR1C3 cells more than in AKR1C3 wild type cells. Meanwhile, colony formation ability was also enhanced after AKR1C3 was over-expressed in MCF-7 cells.Cytoplasmic/nuclear separation analysis and IF further found that β-catenin nuclear translocation mediated by AKR1C3 was the main reason contributing to the occurrence of DOX-resistant breast cancer cells. β-catenin inhibitor, XAV939, could reverse the AKR1C3 induced doxorubicin resistance in MCF-7 cells.Results indicated that AKR1C3 could be a potential therapeutic target in breast cancer cells.