1. There is obvious family susceptibility tendency, especially for those whose immediate family members have breast cancer. 2. Breast hyperplasia, especially atypical hyperplasia, is an important risk factor, and its malignant rate is 2-4%. 3. For patients with breast disease on one side, the chance of breast cancer on the opposite side is 5-7 times higher than that of normal people. 4. Patients with high blood pressure, diabetes mellitus and previous endometrial cancer are the high-risk groups. High-risk physiological factors: early age of menarche, menstrual disorders, late age of amenorrhea, multiple abortions, multiple pregnancies and births, no births or older age of first births, shorter cumulative breastfeeding time, long term use of drugs for contraception, obesity and so on. 6, mental factors: occupational stress, mental instability, negative family life events, low satisfaction with sex life, etc. 7, environmental factors: ionizing radiation, low magnetic field environment, certain chemical substances. 8, high-risk diet: high-fat, low-fiber diet.