To investigate the relationship between metallothionein (MT) and prognosis in breast cancer MT expression was determined with immunohistochemical method (SABC). Results: There was a statistically significant association between expression of MT in breast benign and malignant disease (Ｐ＜0.005). The positive rate was 73.8%(62/84) and 15.0%(3/20) in breast cancer and mastofibroma respectively. The positivity of MT was ber in advanced clinical stages than in early clinical stages. There was no association between MT expression and lymph node metastasis. The mortality of the cancer cases with lymph node metastasis having positive MT expression was higher than those with negative MT expression. Conclusion: MT can be taken as a prognostic index of breast cancer.