Abstract: Endometriosis（EMs） is defined by the presence of visible endometrial implants outside the uterus，mostly occurred in the pelvic organs. The cyclical bleeding of ectopic endometrial lesions leads to serious pelvic pain and infertility of women. EMs is widely viewed as an estrogen-dependent disorder. Progesterone is the classic drug to antagonist estrogen. But in the clinical practice，the majority of the endometriosis patients show low reaction or non-reaction on progestin therapy. Attenuation of progesterone response at the level of the endometrium may be expected to have a deleterious impact on endometrial receptivity and fertility. These phenomena are called progesterone resistance of EMs. The progesterone resistance mechanism involves the defect of the progesterone receptor（PR），the change of progesterone receptor co-regulators and the genetic and environmental factors as well as ERα/ERβ. The aim of this review is to highlight recent findings regarding the progesterone resistance mechanisms and to provide theoretical basis for overcoming progesterone resistance.

Key words: Endometriosis, Progesterone, Receptors, progesterone, Receptors, estrogen