Objective: To investigate the expressions of Oct-4, SOX2 and KPNA2 in triple-negative breast cancer (TNBC) and their clinical significance. Methods: The expressions of Oct-4, SOX2 and KPNA2 in the cancer tissues from 30 TNBC patients and 30 non-TNBC patients were determined by immunohistochemical staining. The relations of their expressions with clinicopathologic factors and prognosis of the TNBC patients were analyzed. Results: In TNBC tissue compared with non-TNBC tissue, the positive expression rates of Oct-4 protein (86.7% vs. 73.3%, P<0.05) and SOX2 protein (90.0% vs. 70.0%, P<0.05) were significantly increased, while the positive expression rate KPNA2 protein showed no significant difference (P>0.05). The expressions of Oct-4, SOX2 and KPNA2 were positively correlated to each other in TNBC tissue (Oct-4 and SOX2: r=0.680, P<0.0001; Oct-4 and KPNA2: r=0.581, P=0.0008; SOX2 and KPNA2: r=0.770, P<0.0001). In TNBC patients, the Oct-4 expression was significantly related to age, histological grade, lymph node metastasis and TNM stage, the SOX2 expression was significantly related to lymph node metastasis and TNM stage, and the KPNA2 expression was significantly related to lymph node metastasis (all P<0.05); the overall survival rate in cases with positive Oct-4, SOX2 or KPNA2 expression was significantly lower than that in those with corresponding negative expression (all P<0.01). Conclusion: The expressions of Oct-4 and SOX2 are increased in TNBC tissue, and they may jointly participate with KPNA2 in the malignant progression of TNBC.