Objective: To explore the expression of human myxovirus resistance protein A (MxA) in triple negative breast cancer (TNBC) and its relationship with prognosis. Methods: 144 cases of TNBC confirmed by pathology before or after surgery from January 2014 to January 2017 in the First Central Hospital of Baoding City were retrospectively collected. Western blotting was used to detect the expression of MxA protein in TNBC and adjacent breast tissues. According to the expression of MxA protein, 144 TNBC patients were divided into low MxA protein expression group (n = 91) and MxA protein high expression group (n = 53) for subsequent comparison of prognosis of patients in between these two groups. Results: The expression of MxA protein in TNBC tissue was lower than that of adjacent breast tissue, and the difference was statistically significant (P<0.05). The patients in high MxA expression group had higher loco-regional recurrence-free rate, disease-free survival (DFS) rate, and overall survival (OS) rate than those in low MxA expression group for 3 years. On the other hand, the distant metastasis rate was lower in the high expression group compared to that in the low MxA expression group, and the difference was statistically significant (P<0.05). Conclusion: In triple-negative breast cancer, high MxA expression is a potential predictor of TNBC prognosis.