In the present study, the investigators will screen breast cancer of the Chinese women based on ultrasound and aim to compare the risk evaluation model of PUMCH model which was established by our previous work with other risk models.

Early detection of breast cancer through screening has been a common practice in the United States and several European countries for decades. It is effective in reducing the mortality of breast cancer and improving the postoperative quality of life of patients. Mammography has been the standard imaging method for the screening, however, our previous study has shown that ultrasound is more sensitive and less expensive than mammography. In the present study, the investigators will screen breast cancer of the Chinese women based on ultrasound and aim to evaluate the risk model (PUMCH model) which was established by our previous work.

Inclusion Criteria:

• Written informed consent；
• residence from community or working units

Exclusion Criteria:

• pregnancy；
• lactation；
• known metastatic cancer；
• signs or symptoms of breast disease；
• presence of breast implants, breast surgery within prior 12 months；
• had mammography or ultrasound exam within prior 12 months
• males.

healthy women without breast-related symptoms