Abstract: Endometriosis is a common disease of women of reproductive age. The invasive
implantation of ectopic endometrium is a complicated procedure, which involves in multiple factors and a few signaling pathways and mitogen activated protein kinase（MAPK）signaling pathway plays the important role. Ectopic endometrium implants and grows on the surface of pelvic organs and followed with bleeding, inflammation and immunifaction and the reaction is steroid-dependent. MAPK signaling pathway makes a difference on stimulating endometriotic stromal cell proliferation, stimulating production of inflammatory factor and neovascularization. Also, it makes T helper （Th）cells drift from Th1 to Th2, and makes the ectopic endometrium implant and grow through immune escaping.

Key words: Endometriosis, Mitogen activated protein kinases（MAPKs）, Signal pathway