Targeted therapy for breast cancer is more suitable for patients with positive or over-expression of her2 receptor, but there are many precautions when using targeted drugs, such as paying attention to adverse reactions, monitoring vital signs and dietary contraindications. 1. Pay attention to adverse reactions: commonly used targeted drugs include trastuzumab for injection, lapatinib tosylate tablets and patuzumab injection, etc. These drugs may cause some adverse reactions in the process of using, such as fever, chills, nausea, vomiting and so on. If the symptoms are mild, then there is no need to worry. However, if the symptoms are obvious, they should be treated promptly. 2. Monitoring vital signs: When taking targeted drugs, doctors should always pay attention to monitoring patients’ vital signs. Once the abnormal phenomenon, then we should promptly carry out a detailed examination to clarify the reasons behind, and then, under the guidance of the doctor for the cause of the treatment. 3. Dietary contraindications: patients should pay attention to the diet, eat less or do not eat spicy and stimulating food, especially seafood, because this kind of food may contain parasites, easy to suffer from bacterial infections, resulting in immune function inhibition, which in turn affects the effect of the targeted drugs. In addition, patients should actively cooperate with the doctor in the process of taking targeted drugs, pay attention to rest, avoid overwork, and maintain sufficient sleep, so as to promote the recovery of the disease and control the development of the disease.