Breast cancer is the most commonly diagnosed cancer and the main cause of cancer deaths among women worldwide. HER2 positive breast cancer accounts for 15% of all breast cancer. This subtype of breast cancer is highly invasive and has a very poor prognosis. With the development of anti-HER2 targeted therapy, the prognosis of these patients has been improved. However, some patients have poor response to the anti-HER2 therapy. Therefore, it is necessary to select biomarkers that can predict the therapeutic effect for improving the efficacy of these patients. This article describes the research progress of HER2 positive biomarkers for breast cancer, focusing on biomarkers related to the efficacy of targeted therapy, in order to provide some reference for future clinical optimization of targeted therapy.