Breast cancer is one of the most common malignant tumors in women, and there is an increasing trend year by year in China, especially in economically developed areas. It is informative to understand the risk of breast development for some targeted strategies. As with many other tumors, the exact cause of breast cancer is not well understood, but related studies have found some factors associated with the development of breast cancer. The following risk factors have been identified: 1. Age The incidence of breast cancer varies uniquely with age and increases with age. 2. Menstruation and childbirth The first menstruation before the age of 12, menopause after the age of 55, and menstruation for more than 40 years are risk factors for the development of breast cancer; having only one child, giving birth at the age of ≥ 30, or not having children, or having repeated abortions are also risk factors for breast cancer. The risk factors are Exogenous estrogens include oral contraceptives containing estrogen and estrogen replacement therapy for postmenopausal women. Weight gain after menopause is also a risk factor for the development of breast cancer. The determining factor of estrogen and progesterone levels in the body after menopause is body fat content. 5.Food and regional culture Alcohol consumption can increase the risk of breast cancer to some extent. The higher the number of relatives with breast cancer, the closer the relatives, the younger the age of the disease, and the more the number of bilateral cancers, the higher the risk of breast cancer for the female relatives concerned. The incidence of bilateral breast cancer is 4–5 times higher in BRCA1 and BRCA2 gene mutation carriers than in dissemination. Factors that have been proven or suggested to be protective against breast cancer include: 1. breastfeeding breastfeeding for at least 6 months per child; 2. regular physical activity including insisting on household activities and insisting on work, less travel by car and elevator, more walking and bicycling; 3. more childbirth.