Objective：To investigate the effect of different down-regulation protocols on the outcome of in vitro fertilization-embry－otransfer in patients with endometriosis. Methods：Clinical data of 108 patients with endometriosis who underwent in vitro fertilization-embryo transfer in the reproductive center of the Third Affiliated Hospital of Zhengzhou University from January 2010 to December 2012 were analyzed． According to the different down-regulation protocols，patients were divided into two groups：prolonged therapy group（n=33） and super prolonged therapy group（n=75）. Outcome of assisted reproduction between the two groups was analyzed. Results：There was no obvious difference in patients’ age，infertility duration，basic of follicle-stimulation hornone，luteinizing hormone and estradion levels（P >0.05）. Total duration and dosage of gonadotropin were obvious higher in super prolonged therapy than in pro－longed therapy group，but the number of oocytes and cleavage，number of transferable embryo and number of high quality embryo were fewer in super prolonged therapy than in prolonged therapy group（P<0.05）. Clinical pregnancy rate and embryo implantantion rate were higher in super prolonged therapy than in prolonged therapy group（P<0.05）. Conclusions：Use of super prolonged protocol regulation can improve embryo implantantion rate and pregnancy rate for patients with endometriosis at Ⅲ-Ⅳ stage.