Objective To investigate the proportions of CD4+ T cells, CD8+ T cells, and mutant of p53 gene in the microenvironment of breast infiltrating ductal carcinoma, and to explore its’ correlation with prognosis of breast infiltrating ductal carcinoma. Methods Eighty-five cases of breast infiltrating ductal carcinoma were collected who underwent surgery in the 371st Central Hospital of Peoples’ Liberation Army from 2010 to 2012, and then detected the proportion of CD4+ T cells and CD8+ T cells, ratio of CD4+ T cells to CD8+ T cells, and mutant of p53 gene in the cancer tissues with immunohistochemistry. Comparison between the sentinel lymph node metastasis group and non-sentinel lymph node metastasis group, mutant of p53 gene group and non-mutant of p53 gene group on the proportions of CD4+ T cells, CD8+ T cells, and ratio of CD4+ T cells to CD8+ T cells were performed, as well as the relationship between proportion of CD8+ T cells/mutant of p53 gene and prognosis of breast infiltrating ductal carcinoma. Results ① The relationship between proportion of CD4+ T cells/proportion of CD8+ T cells/ratio of CD4+ T cells to CD8+ T cells and situation of sentinel lymph node metastasis: at cluster, compared with the sentinel lymph node metastasis group, the proportion of CD8+ T cells was lower in the non-sentinel lymph node metastasis group (P<0.05), but there was no significant difference on the proportion of CD4+ T cells and ratio of CD4+ T cells to CD8+ T cells (P>0.05); at stroma, compared with the sentinel lymph node metastasis group, the proportions of CD4+ T cells and CD8+ T cells were lower, but the ratio of CD4+ T cells to CD8+ T cells was higher in the non-sentinel lymph node metastasis group (P<0.05). ② The relationship between proportion of CD4+ T cells/proportion of CD8+ T cells/ratio of CD4+ T cells to CD8+ T cells and mutant of p53 gene: both at the cluster and stroma, compared with the mutant of p53 gene group, the proportions of CD4+ T cells and CD8+ T cells were lower, but the ratio of CD4+ T cells to CD8+ T cells was higher in the non-mutant of p53 gene group (P<0.05). ③ The relationship between proportion of CD8+ T cells/mutant of p53 gene and prognosis of breast infiltrating ductal carcinoma: the prognosis was worse in patients with high degree of infiltration of CD8+ T cells and mutant of p53 gene than those patients with low degree of infiltration of CD8+ T cells and non-mutant of p53 gene (P<0.05). Conclusions The proportions of CD4+ T cells and CD8+ T cells, and ratio of CD4+ T cells to CD8+ T cells are associated with the situation of sentinel lymph node metastasis and mutant of p53 gene, and the degree of infiltration of CD8+ T cells and mutant of p53 gene are associated with the prognosis of breast infiltrating ductal carcinoma.