Objective: This research to be confirm the identifed the sentinel lymph node by blue methylen in breast cancer patient. Patients and methods: Blue methylen injected for mapping and identifying sentinel node on 76 patients with breast cancer. All the patients underwent a modified radical mastectomy. Tumor and lymph node were processed for histologic examination using Hematoxylin and Eosin. Results: Sentinel lymph nodes were indentified in 90.8 percent., false negative of 16.7 percent, sensitivitive of 83.8 percent, negative predictive value of 88.6 percent, accuracy rate of 92.8 percent. In group Tl, T2 , No, these index respectively were 93.9 percent
9.1 percent
90.9 percent
97.2 percent
97.8 percent. Conclusion: Sentinel node identification by blue methylen and the sentinel lymph node biopsy by blue methyl en were possibility and reliability.