Objective:To investigate the immune function of Axilla lymph nodes which cancer cells metastasis and not metastasis in breast cancer. Methods:It used flow cytometry to calculate the percent of lymphocyte subsets of the axilla lymph nodes and compare the result with each other between August 2004 and July 2005. Results:Whether cancer cells metastasis to the axilla lymph nodes or not,the percentage of lymphocytes CD3+T、CD4+T、CD8+T、CD16+NK、CD19+B had no statistical difference (P>0.05).When cancer cells metastasis to SLN,the percentage of lymphocytes CD4+T、CD8+T、CD16+NK had statistical difference (P<0.05),and the percentage of CD3+T、CD19+B had no statistical difference (P>0.05). Conclusion:When the axilla lymph nodes has no cancer cells metastasis,it’s immune function is natural.Once lymph nodes has cancer cells metastasis,it’s immune entironment is transformation,and so the immune function is bated.