Abstract: Endometriosis (EMs) is a benign lesions on pathology, but it has similar characteristics with malignant tumor such as infiltration, plant growth and damage the surrounding tissue, distant metastasis, and easy to relapse. Moreover, having a certain proportion of EMs histomorphology changes will happen, from atypical endometrial ectopic tissues further into cancer. Recently, EMs malignant transformation has received extensive attention of scholars from all over the world. Although the connection between EMs and ovarian cancer has been reported by scholars and has accepted diagnostic criteria, with the increase of the incidence of endometriosis and ovarian cancer, etiology, mechanisms and the epidemiological characteristics of endometriosis-associated ovarian cancer（ＥＡＯＣ） have become a research focus in recent years. This artical is to review the current data regarding the pathogenesis of EMs malignant transformation associated with gene mutation, apoptosis, inflammation, immunity, oxidative stress, estrogen.