In recent years,although many advances have been made in the treatment of breast cancer,its incidence is still on the rise,and the search for new drug targets and biomarkers has become a research hotspot.More and more clinical studies are paying attention to the interaction between tumor cells and tumor microenvironment,and it is believed that tumor microenvironment plays a crucial role in the progression of malignant tumors.Substance P(SP)can participate in the process of carcinogenesis and play a crucial key role in maintaining the tumor microenvironment.Neurokinin 1 receptor(NK-1R)is expressed in the cytoplasm of tumor cells and is significantly associated with many tumor characteristics.SP induces tumor cell proliferation,angiogenesis and migration through its receptor NK-1R,and exerts anti-apoptotic effects.In future treatment plan,whether NK-1R antagonists can be used to provide more accurate targets for the diagnosis and treatment of breast cancer has become a hot topic.This article reviews the research status of SP/NK-1R system in breast cancer.