Phyllodes tumors of the breast are rare fibroepithelial neoplasm which are generally divided into benign, borderline, or malignant. In this case study, we reported a 40-year-old female presented with an asymptomatic right breast mass underwent sonographic evaluation. The surgical histopathology was diagnosed as borderline phyllodes tumor. Sonographic features of the tumor are described in detail, and the relevant literatures are reviewed and discussed.