Background: BRCA1 and BRCA2 genes have been proven to be genetic susceptibility genes for breast cancer. Their mutations are closely related to hereditary breast cancer, and can also increase the risk of other cancers. Several studies have been conducted to examine the distribution and prevalence of BRCA1 and BRCA2 mutations as well as the penetrance of breast cancer in BRCA1/2 mutation carriers among different populations. However, most studies conducted among Chinese were hospital-based research, which may not reflect the real epidemiology in the population. In order to fill the gaps in community research, this study aims to screen genetic susceptibility genes of breast cancer patients in the Chinese community and establish a cohort of genetic high-risk populations. Methods: This is a multisite, prospective, cohort study which has been ongoing in 3 provinces of eastern China since 2019. Up to 5,000 breast cancer survivors will conduct BRCA1, BRCA2, PTEN, CHEK2, and PALB2 genetic susceptibility genes testing, provide clinical and genetic information and family history. Participants were followed up based on the results. Discussion: This is the first study of breast cancer and other common malignancies penetrance and genetic susceptibility gene mutation carrying possibility which is based on community breast cancer data. It is superior to data from hospitals and high-risk clinics. The establishment of a mutation prediction model suitable for the Chinese population still has high socio-economic value.