The metastasis has been a focus and difficulty in the treatment of breast cancer，and its invasiveness is strongly influenced by the surrounding stroma.Cancer-associated fibroblasts(CAFs)，the key components of the tumor stroma，are positive for the novel membrane estrogen receptor—G protein coupled estrogen receptor(GPER).Studies have shown that GPER may be a pivot of multiple transducers acting on cancer cells and the tumor microenvironment，and the activation of GPER in CAFs plays a key role in the occurrence，progression，and metastasis of breast cancer.The anti-breast cancer effects of a number of active components in Chinese medicines are associated with the GPER pathway in CAFs.We introduced the mechanism of GPER activation in CAFs，the effect of GPER activation on breast cancer metastasis，and the intervention of active components in Chinese medicines in the GPER pathway，aiming to underpin the discovery of new targets and the development of new therapeutic schemes for breast cancer.