Objective To investigate the pathological features of pregnancy associated breast cancer （PABC）and its influence on clinical prognosis. Methods We retrospectively analyzed the data of 54 PABC patients，and age ⁃matched with 108 controls from January 2009 to December 2017. The clinical and pathological characteristics including the rates of（overall survival，OS）and（disease⁃free survival，DFS）of the patients in the two groups were compared and the factors affecting the prognosis of breast cancer were analyzed. Results PABC tumors were more advanced in tumor size，axillary lymph node involvement，carcinoma in a vessel，the negative rates of progesterone receptor（PR）and estrogen receptor（ER）（P < 0.05）. The OS and DFS of PABC group were lower than those in the control group（P < 0.05）. Multivariate analysis revealed that pregnancy status， advanced tumor size，nodal involvement，and carcinoma in a vessel were related with poor DFS and OS（P < 0.05）. Conclusion Pregnancy ⁃ associated status is a strong prognostic factor of OS and DFS in BC. Further studies should focus on biologic specificities and pathological features of PABC，providing evidence for the treatment and prognosis of PABC.