Objective To study diagnosis, treatment and prognosis of multiple primary breast carcinoma. Methods The data of 6 patients with multiple primary carcinomas correlated with breast carcinoma were summarized. First and second primary breast carcinoma were treated by radical operation or with radiotherapy and chemotherapy. Result 3 patients (50% ) happened recurrences of carcinoma were followed up. Conclusion The causes of genesis of second primary carcinoma and recurrence of primary carcinoma were related with suppression of immunological function and also biological property of carcinoma.