Abstract: Objective 　To evaluate the outcome and prognosis analyze of bilateral primary breast cancer (BPBC) . Methods 　The clinical data of 222 patients with BPBC, admit ted to Tianjin Medical University Cancer Institute and Hospital from March 1972 to December 2003 were collected and analyzed on prognosis factors. Results 　5-year and 10-year Cumulative Survival rate of BPBC were 78. 73 % and 69. 09 %. Cumulative Survival rate of sBPBC(Synchronous BPBC, sBPBC) is lower than mBPBC's (Metachronous BPBC, mBPBC), but there is no significant difference. The status of bilateral lymph node of and tumor size of secondary cancer affect the survival of BPBC significantly. Conclusion 　The survival rate of sBPBC is similar to that of mBPBC. The prognosis of patient s with negative lymph node of two sides and tumor size < 5cm of secondary cancer are better than those with positive lymph node and tumor size ≥5cm. The results of multivariate analysis showed that tumor size of secondary cancer and lymph node status ofbilateral breast cancer are prognostic factors of bilateral primary breast cancer.