Ultrasound and mammography are completely different examinations, reflecting different aspects of breast tissue and lesions, each with its own advantages and disadvantages, and cannot be substituted for each other, as follows: 1. The advantages of breast ultrasound examination are real-time, convenient, safe, and radiation-free, which can show the monolayer anatomical structure of breast glandular tissue, thus discovering the internal structural changes of the tissue, mainly used in breast occupational diseases and daily check-ups, and can make a clear diagnosis of the disease It is mainly used for breast occupational disease and daily examination, and can make clear diagnosis and differential diagnosis of the disease. However, ultrasound has a low detection rate for microcalcifications and is less accurate. For early lesions, the lack of analysis of gross morphological changes may produce a missed diagnosis; 2. Mammography is significantly better than color ultrasound in observing calcification of breast lesions, and it is more sensitive to see subtle lesions. However, the specificity is lower. Mammography is superior in observing macroscopic structural distortion and tissue symmetry, but it is difficult to determine the dense lesion condition of the breast. Some disease examination procedures require a comprehensive analysis of both in combination with each other to provide a clinical basis for diagnosis.