Abstract: Abstract Objective：To discuss the pathological feather and correlated risk factor of malignant of endometriosis．Methods：4234 endometriosis cases from 2000 to 2005 were analyzed retrospectively, Surgical treatment and pathological examination confirmed endometriosis．Results：Patients were divided into two groups based on pathological diagnosis.Dysmenorrhea and alter of menses were more frequent in group A（81.8%）, abdominal distension and mass of pelvic cavity were more frequent in group B（χ2=56.88，P<0.01）. There were 2041 diameter of tumor in group A in 4178 cases exceed 8cm(49.5%)，diameter of tumor of 41 cases of group B exceed 8cm (73.2%), the distinction has statistical significance (P< 0.01) . Beyond surgry 357 cases’s value of CA125 is higher than 100U/ml in group A（8.7%），15 cases’s value of CA125 is higher than 100U/ml in group B（26.8%）。Age of 2953 cases in group A less than 40(71.6%）, age of 19 cases in group B less than 40(33.9%）, the distinction has statistical significance (P< 0.01) . Makes a follow-up visit for 5 years, five year survival rate of pure ovarian cancer of group A is 92.4%, group B is 46.9%. Condiusion：Patients with risk factors of diameter of tumor exceed 8cm or CDFI accompanied by substantial mass or CA125 is higher than 100U/ml ,surgical treatment is used for patients with risk factor,so to find the patients who was conbined with ovarian cancer.So we shoule pay higher attention to it in the linical work.

Key words: Endometriosis Ovarian neoplasms Prognosis Malignant Five year survival rate