Abstract: Objective To investigate the clinical and pathological features of primary bilateral breast cancer (BPBC). Methods Medical records of BPBC patients were reviewed from the Tianjin Medical University Cancer Institute and Hospital during 1.1971—11.2011 Data of the synchronous and asynchronous breast cancer were analyzed,including the age of tumor onset，the time interval between two cancer，menstruation，family history，the size of tumor，clinical stage，pathologic characteristics. Results First cancer onset age of the asynchronous breast cancer was earlier than that of synchronous breast cancer(P<0.05).There were no statistical difference between synchronous and asynchronous breast cancer on family history，the size of tumor，clinical stage and pathologic characteristics(P>0.05).The concordance rate of endocrine receptors in synchronous was higher than that in asynchronous breast cancer(P<0.01). Clinical stage,tumor size and the number of involved axillony nodes of the second tumor in both synchronous and asynchronous breast cancer were lower than those of the first tumor.The difference of five-year disease-free survival and ten-year overall survival between synchronous and asynchronous breast cancer had statistically significant(P<0.01). Conclusion The first tumor and the second tumor could been seen as independent disease.Surveillance was necessary to screen the contralateral breast cancer once the primary breast cancer occurred.Five-year disease-free survival and ten-years overall survival in asynchronous breast cancer was higher than those in synchronous breast cancer.