During the IVF ovulation promotion process, careful friends will find that there are various IVF ovulation protocols depending on individual patient differences, ovarian function and causes of infertility. The common ones are long regimen, short regimen and ultra short regimen, but there are also patients who apply the ultra long regimen. The ultra-long regimen is to use long-acting gonadotropin-releasing hormone (GnRH) agonist for one to several months before the ovulation treatment, and then start ovulation promotion only after all the indicators meet the ovulation standards. Currently, these regimens are mainly used for patients with endometriosis. The prevalence of endometriosis in the female population is about 10%, while it is responsible for about 20-30% of infertility in women. In patients with endometriosis, the clinical pregnancy rate of their traditional methods of pregnancy assistance is lower than that of patients with other infertility factors, while the extra-long protocol can better suppress the ectopic lesions in endometriosis patients and control the inflammatory response in the pelvis, so the extra-long protocol can well improve the pregnancy assistance outcome in endometriosis patients. It is the most commonly used regimen for patients with endometriosis. In recent years, with the rich experience in ovulation promotion, clinicians found that the ultra-long protocol can not only improve the hormone level and pelvic environment, but also has a good effect on the endometrium, so the ultra-long protocol is now gradually being widely used in patients with polycystic ovary syndrome, patients with hyper-LHemia, and patients with repeated implantation failure. The specific protocols have also been optimized, and modified ultra-long protocols have emerged, among others. In any case, the most suitable protocol is chosen according to the patient’s specific situation, with the aim of achieving the highest clinical pregnancy rate.