In this study, the human breast cancer-bearing nude mice model has been established and the radioimmunoimaging was carried out by using human anti-human monoclonal antibodies. The results showed that the breast tumor-bearing nude mice received 131I-McAb-CM-1 had a clear image of the xenograft during 4 to 6 days after injection and at the same time T/NT all over 1.0. The highest T/NT reached 7.1. It demonstrates that McAb-CM-1 can specially combine with breast cancer tissues and hopefully it could be used clinically to improve accurate rate of the early breast cancer diagnosis.