Objective: The aim of this study was to detect the expression level of Metadherin (MTDH) in peripheral blood of the breast cancer patients by real-time fluorescence quantitative polymerase chain reaction (PCR), and to explore the relationship between expression of Metadherin gene in the patients peripheral blood and the clinic-pathological features in breast cancer. Methods: Real-time fluorescence quantitative polymerase chain reaction was employed to determine the ex-pression level of Metadherin gene in 80 peripheral blood samples of breast cancer patients and healthy donors. Results: The expression of Metadherin gene in breast cancer patients peripheral blood were positive, in which 34 breast cancer patients were highly expressed, accounting for 55.7%, while the expression of Metadherin gene in normal females peripheral blood were negative, there was statistical significance (Ratio = 2.02±0.81, P < 0.05); Ratio of the Metadherin expression in breast cancer patients peripheral blood and the glyceraldehyde-3-phosphate dehydrogenase expression was 1.15±0.36. REST software analysis showed that the expression of Metadherin gene was significantly up-regulated in breast cancer. Conclu-sion: The SYBR Green Ⅰ quantitative real-time polymerase chain reaction method can successfully detect the expression level of Metadherin gene. Expression level of Metadherin gene in breast cancer patients peripheral blood is closely related to survival, and it maybe involved in the development of breast cancer and used as an indicator of prognosis.