Abstract: Objective : To evaluate the accuracy and the clinical significance of the sentinel lymph node biopsy in predicting the axillary lymph node status of the breast cancer patients. Methods : In ourstudy, there were 41 patients with primary breast cancer, clinically TNM stage I and Ⅱ in negative axillae. Mapping procedures and SLNB were performed using methylene blue injected at the site of the primary breast cancer, followed by the axillary lymph node dissection. All of the SLN and ALN were evaluated pathologically (HE) after the operations. Results : A total of 32 in 41 cases (78.0%), SLN were identified. Of them, the group one, (T₁ , T₂) N₀M₀ , had the axillary nodal status accurately predicated in 24/25 (96%); 0 in 22 (0%), the SLN was false-negitive, Both overall positive and negative predicative values were 100%. In the group (T₁T₂) N₁M₀, there were the axillary nodal status accurately predicated in 4 of 7 cases (57.1%); in 2 of 7 cases with the false-negative SLN. Conclusion : Our study indicates that intraoprative lymphatic mapping using methylene blue and SLN can accurately predict the axillary lymph node status of the (T₁, T₂) N₀M₀cancer patients.