Pediatric breast masses are relatively rare and most are benign. Most are either secondary to normal developmental changes, Infections,trauma,endocrine disorders, or neoplastic processes with a relatively benign behavior. To fully understand pediatric breast disease, it is important to have a firm comprehension of normal development and of the various tumors that can arise. Physical examination and targeted history (including family history) are key to appropriate patient management. When indicated, ultrasound is the imaging modality of choice. Biopsy is contraindicated as this may lead to significant breast deformity so knowledge of the sonographic appearance of normal breast development and specific lesions is most helpful in identifying and characterizing abnormalities.US has wide acceptance because of density of breast at this age and its lack of radiation hazards.