【Objective】To compare the clinical outcomes of fresh embryo transfer of the in vitro fertilization/intracytoplasmic sperm injection and embryo transfer（IVF/ICSI-ET）in different age groups as well as in different responders using gonadotropin-re? leasing hormone agonist（GnRH-a）long protocol or GnRH antagonist（GnRH-ant）protocol.【Methods】A retrospective analysis was performed on 737 IVF/ICSI cycles，including 386 cycles of GnRH-a long protocol（group A）and 351 cycles of GnRH-ant protocol （group B），from August 28，2015 to December 31，2016. Then all the cycles were divided into sub-groups by ages and retrieved oo? cyte numbers：group a1（< 38 years），group a2（≥ 38 years）；group b1（n ≤ 5），group b2（6 ≤ n ≤ 15），group b3（n > 15）. Thebasic information of patients and clinical outcomes were compared.【Results】（1）Comparable results were obtained from group A and group B in these following variables such as fertilization rate，normal fertilization rate，biochemical pregnancy rate and miscarriage rage. But the stimulation period，the total gonadotropin（Gn）dosage，estradiol（E2）level and endometrial thickness on the day of human chorionic gonadotropin（hCG）administration，number of oocytes retrieved and mature oocytes，ovarian hyperstimulation syn? drome（OHSS）rate，implantation rate and clinical pregnancy rate were significantly higher in group A than group B（P < 0.05），and significantly higher cancellation rate of fresh embryo transfer was observed in group B（P < 0.001）.（2）When divided by ages，no mat? ter in sub-group a1 or sub-group a2，the implantation rate was slightly lower in GnRH-ant protocol than in GnRH-a long protocol， although they failed to reach significant difference（sub-group a1：32.6% vs 39.8%，P = 0.067；sub-group a2：9.7% vs 17.9%，P = 0.066）. The clinical pregnancy rate was comparable using these two protocols in sub-group a1（54.8% vs 50.4%，P = 0.429），but it was significantly lower by using GnRH-ant protocol than GnRH-a long protocol in sub-group a2（19.6% vs 39.1%，P = 0.021）. （3） When divided by numbers of oocytes retrieved，the implantation rate was significantly lower when using GnRH-ant protocol in sub- group b1（13.1% vs 26.0%，P = 0.026），but we failed to observe significant differences in other two sub-groups. The clinical preg? nancy rates were comparable in all sub-groups，whereas differed considerably in sub-group b1（36.6% vs 19.3%，P = 0.056）. 【Conclusion】Overall，the implantation rate and clinical pregnancy rate were higher in GnRH-a long protocol than those in GnRH- ant protocol. Nevertheless，GnRH-ant protocol could reduce the dosage of Gn，shorten the treatment duration，and effectively reduce the occurrence of OHSS. There were similar pregnancy outcomes in two protocols for normal responders and high responders，while for advanced patients or other poor responders，the implantation rate and clinical pregnancy rate were higher in GnRH-a protocol.