It was found that the positive expressions of Ki67 and Topo IIα in the breast cancer tissues were higher than those in the normal tissues; the positive expression rate of Ki67 was in a correlation with diameter of breast cancer and lymphatic metastasis (P<0.05); the positive expression rate of Topo IIα was in a correlation with clinical stage, diameter of cancer and lymphatic metastasis (P<0.05). This evidence concerns the gene MKI67 and breast carcinoma.