Breast cancer is a highly heterogeneous tumor, and the traditional pathomorphological staging has gradually shown its imperfection in current clinical practice. With the completion of the Human Genome Project and the application of molecular biology techniques, the concept of molecular typing based on tumor morphology combined with gene expression characteristics has been recognized by scholars. The genetic phenotype and clinicopathological characteristics of each molecular subtype of breast cancer 1. LuminalA: It is the most common molecular subtype of breast cancer with the incidence of 44.5%-69.0%. ER and/or PR+, Her-2C, has the best prognosis. Endocrine therapy has the best outcome. Endocrine therapy (± chemotherapy) is often used. Premenopausal often choose triamcinolone acetonide, pharmacological depot drug Norelide, postmenopausal often choose aromatase inhibitors such as anastrozole, letrozole, etc. 2.LuminalB type: luminalB type is 7.8%, ER and/or PR+, Her-2+, endocrine therapy is still effective and has a better prognosis. luminalB breast cancer is less responsive to tamoxifen than luminalA type due to positive HER2 expression, but endocrine therapy with other mechanisms of action is still effective instead. Treatment is often done with chemotherapy + endocrine therapy + targeted therapy. Her-2 overexpression type: incidence is 14.7%, ER and/or PRC, Her-2+, endocrine ineffective, chemotherapy is more effective, and is an indication case for HER2-targeted therapy Herceptin treatment, HER2(+) type breast cancer is significantly more effective than luminal type for cyclophosphamide combined with anthracycline chemotherapy regimen, the clinical remission rate of the former is up to 70%, while the latter is 47%. The former had a clinical remission rate of 70% compared with 47% for the latter. Although this type is more sensitive to chemotherapy, the clinical prognosis is poor. Chemotherapy + targeted therapy is often used, and 1 year of Herceptin treatment can reduce the relative risk of recurrence by 52% and increase disease-free survival by 12% at 3 years. 4, Basal-like type: incidence is 17.1%, ER and/or PRC, Her-2C, endocrine ineffective, chemotherapy effective, and worst prognosis. Its metastases mostly occur in the viscera and central nervous system. Treatment options are chemotherapy. Among breast cancer patients receiving preoperative neoadjuvant chemotherapy, there is a high overall response rate and pathological remission rate, with 85% of patients showing clinical remission, of which 27% achieve pathological complete remission, significantly higher than luminal type breast cancer. Although sensitive to preoperative neoadjuvant chemotherapy and with a high pathological remission rate, it still has the worst prognosis among the molecular subtypes of breast cancer. Breast cancers with identical pathological morphology show high heterogeneity at the molecular level due to molecular genetic alterations, which leads to wide differences in prognosis and response of tumors to treatment. Breast cancer genotyping, however, proposed based on gene expression profiling and gene microarrays, can more accurately respond to the biological behavior of tumors, determine prognosis, and facilitate the selection and study of more targeted and personalized treatments. An individualized and systematic treatment plan should be developed based on each patient’s molecular typing and other relevant factors.