Breast staging is a concise description of the composition of the entire breast after attenuation of X-rays through the breast tissue and helps to determine the degree of reliability of the X-ray diagnosis, i.e., the likelihood that the lesion is hidden in normal breast tissue. For X-ray dense breast, the ability to detect small lesions on X-ray decreases as the denseness of the breast gland rises, and clinicians should be well aware of this. There are four types: ① Fatty: the breast tissue is almost completely replaced by fatty tissue. ②Small amount of glandular type: there are scattered fibroglandular shadows. ③Multiple glandular type: the breast tissue is unevenly distributed and shows uneven density changes. This type reduces the sensitivity of lesion detection. (iv) Very dense breast tissue type: may obscure lesions in it.