Objective: To investigate the expression and clinical significance of L-selectin in sentinel lymph node (SLN) of human breast cancer, so as to clarify the relation of SLN status with the expression of L-selectin. Methods: Sixty-eight patients with T1-2N0M0 breast cancer were selected. SLN biopsy (SLNB) was performed using 1% methylene blue dye, and then the L-selectin expressions in the SLNs, tissues of primary lesions and tumor adjacent tissues along with the tissues from 20 cases of stage III atypical hyperplasia were detected by immunohistochemical staining methods. Results: The SLNs were successfully identified in 62 of the 68 patients, so the detection rate was 91.17% (62/68). There were 3 false negative cases. The L-selectin expression level in the positive SLNs was significantly higher than that in the primary tumor tissues and adjacent tissues (both P<0.05); in the primary tumor tissues of the SLN positive cases it was significantly higher than in those of the negative ones (P<0.05), and in the primary tumor tissues of both SLN and non-SLN positive cases it was significantly higher than in those of both SLN and non-SLN negative ones (P<0.05). Conclusion: The L-selectin expression level increases in SLN positive breast cancer, which suggests that L-selectin plays an important role in lymphatic chemotactic metastasis of breast cancer. SLN status was closely related with the L-selectin expression in breast cancer, and the combination analysis of both can more comprehensively reflect the metastastic pattern of breast cancer and status of the axillary lymph node.