Objective：To investigate effect of HMG-CoA reductase degradation protein 1（HRD1） on the proliferation and migration of breast cancer cells. Methods：The expression of HRD1 and lactate dehydrogenase B（LDHB） was detected by Western blot in breast cancer tissue specimens and matched adjacent normal breast tissues；The expression of HRD1 and LDHB in MDA-MB-231 and MCF-7 cells transfected with adenovirus over-expressed HRD1 were detected by Western blot. Cell MTT assay，colony-formation assay，and transwell assay were performed to detect cell proliferation and cell migration rate，respectively. Results：Compared with the control group，the protein expression of HRD1 in matched adjacent normal breast tissues was increased，whereas，the protein expression of LDHB was decreased（P＜0.05）. A decline in cell proliferation and migration were found in MDA-MB-231 and MCF-7 cells transfected with adenovirus over-expressed HRD1（P＜0.05）. Conclusion：Overexpression of HRD1 results in the inhibition of growth and migration in human breast cancer cells. It downregulates the LDHB protein levels of human breast cancer cells.