Breast cancer is one of the most common malignant tumors in women, and its incidence rate is increasing year by year. The incidence rate of breast cancer has risen to the first place among female malignant tumors in many major cities in China, becoming the biggest threat to women’s health. Although these treatments have achieved some success, almost all advanced breast cancers and many early stage breast cancers eventually fail to be treated. The special structure and mechanism of action of conventional chemotherapeutic agents determine their poor selectivity and resistance to drugs. Therefore, the development of anti-breast cancer drugs with high selectivity and sensitivity is the urgent need to improve the level of comprehensive breast cancer treatment. The emergence of molecular targeted therapy has brought new hope to breast cancer patients. Molecular targeted therapies are aimed at targets that may lead to cellular carcinogenesis, such as proto-oncogenes and oncogenes, cell signaling pathways, cytokines and receptors, and anti-tumor angiogenesis, to reverse the malignant biological behavior at the molecular level and thus inhibit the growth of tumor cells. Molecular targeted therapy for breast cancer is another effective clinical treatment after chemotherapy and endocrine therapy. The development of molecular targeted therapy in medical oncology for 50 years in drug development has focused on cytotoxic aggressive agents. Although after anthracyclines (Adriamycin, Epiaminomycin) and platinum (Cisplatin, Carboplatin), many powerful chemotherapeutic drugs such as Tysol, Tysodex, Kepto, Platinium Oxalate, Kinzel, etc. were introduced and played important roles in different cancers, their nature still belongs to drugs that cannot distinguish tumor cells from normal cells, and their clinical application is limited by many factors. Today, in the 21st century, molecular targeted therapy is no longer a new term. As scientists continue to explore the molecular biology of cancer pathogenesis, they realize that if we can target the specific molecular changes of cancer, it will greatly improve the therapeutic effect and trigger a change in the concept of anti-cancer treatment. In recent years, new molecular targeted drugs have achieved remarkable efficacy in clinical practice, which has demonstrated the correctness and feasibility of molecular targeted therapy theory, among which Herceptin is the most representative drug at present. After years of development, targeted therapies have become more mature, and there are many targeted drugs with definite efficacy, which will benefit more breast cancer patients. However, how to find the real tumor cell specific target; how to select the best target for benefit; resistance to targeted drugs; early evaluation of the efficacy of targeted drugs and the cost of the most practical targeted drugs, etc. are also troubling the research and clinical application of new drugs, and solving these problems will certainly make the treatment of breast cancer enter a new era of “truly individualized treatment”. To solve these problems, breast cancer treatment will enter a new era of “truly individualized treatment”.