Abstract: Objective To detect the expression and distribution of CD20+B and CD3+T lymphocytes in breast cancer, discuss the relationship between the prognosis of breast cancer and lymphocyte infiltration. Methods Using immunohistochemistry(IHC) to investigate the expression of CD20 and CD3 in 44 medullary carcinoma cases and 128 cases of infiltrating ductal carcinoma, the relationship between the expression differences and prognosis was analyzed, Kruskal-Wallis Test was used among groups, Chi-square Test was used within the group. Results (1)There was a higher numbers of CD20+B lymphocytes and CD3+T lymphocytes in medullary carcinoma than that in infiltrating ductal carcinoma （P＜0.05）. Both of CD20+B lymphocytes and CD3+T lymphocytes located in peritumoral were more than that in intratumoral of infiltrating ductal carcinoma.（2）The higher numbers of CD20+B lymphocytes and CD3+T lymphocytes was associated with the longer disease-free survival in infiltrating ductal carcinoma（P＜0.05）.（3）CD20+B lymphocytes was negatively correlated with tumor grade，pTNM，nodal stage and recurrence（P＜0.05）；CD3+T lymphocytes was negatively correlated with tumor grade，nodal stage and recurrence（P＜0.05）. Conclusion There are different expression of CD20+B and lymphocytes CD3+T lymphocytes in infiltrating ductal carcinoma，and medullary carcinoma and the lymphocytes was associated with prognosis.