Abstract: Objective: To investigate the role of scatter factor (SF) in the development of human breast cancer and the relationship with the biological characteristics of human breast cancer. Methods: The concentration of plasma SF in 60 patients with breast cancer and 30 patients with breast begin lesion and 20 healthy women were measured by using the quantitative sandwich enzyme -linked immunoassay technique. Results: The content of plasma SF in patients with breast cancer was significantly higher than that of the healthy woman and the patients with breast begin lesion (P<0.01). The content of plasma SF decreased significantly after surgery (P<0.01). The plasma SF level was correlated with tumor size, node status and TNM stage (P<0.05). Conclusions: SF may play an important role in the development and progression of human breast cancer and was correlated with the biological characteristics of human breast cancer. So, it can be an molecular marker of diagnosis, metastasis and prognosis in breast cancer.