Abstract: Objective 　In order to avoid axillary dissection in the patient s without lymph node metastases, factors associated with metastases of non-SLN should be found to prognosticate whether non-SLN has metastases. Methods 　A database including 116 breast cancer patient s who underwent SLN biopsy between May, 1999 and Febrary, 2004 was reviewed. Using sof t ware SPSS 10. 0 univariate and multivariate analysis were performed to evaluate the relationship between 10 factors and non-SLN metastasis in order to find which factor is associated with metastasis . Results 　Tumor size greater than 2cm, lymphatic invasion, c-erbB2 ( + ) were positively correlated with metastasis in non-SLN. When a patient has one factor, the metastasis rate of non-SLN is 91%～95%, when has two factors, the rate is 94 %～100 %, when has three factors, the rate is 100 %. Conclusion 　SLN biopsy combined with prognosis of non-SLN help patients with metastases only in SLN to avoid axillary dissection, and then the t reatment will be more purposive than before.