Objective To evaluate the effectiveness of GnRH antagonist on vitro fertilization-embryo transfer (IVF-ET). Methods We searched CBMdisc (1979 to 2010), Wanfang (1994 to 2010), CNKI (1994 to 2010), VIP (1989 to 2010), PubMed (1997 to 2010), PML (1997 to 2010), FMJS (2000-2010), and 9 related journals to identify randomized controlled trials (RCTs) on the comparison between GnRH antagonist (GnRHA) and GnRH agonist (GnRHa). The quality of included trials was critically appraised. RevMan 4.2.7 software was used for statistical analysis. Results Six published RCTs involving 1 208 participants were included. Compared with the GnRHa group, stimulation duration in the GnRHA group was lower (WMD= –1.07, 95%CI –1.38 to –0.76), dose of gonadotrophins (Gns) in the GnRHA group was slightly lower (WMD= –0.49, 95%CI –1.63 to 0.66), endometrial thickness at the time of HCG administration was no significant difference in the two groups (WMD= –0.09, 95%CI –0.42 to 0.24), number of oocytes retrieved in the GnRHA group was lower (WMD= –1.80, 95%CI –2.48 to –1.12), OHSS rate in the GnRHA group was slightly lower (Peto OR= 0.77, 95%CI 0.35 to 1.72), pregnancy rate in the GnRHA group was slightly lower (Peto OR= 0.83, 95%CI 0.65 to 1.05), miscarraige rate as no significant difference in the two groups (Peto OR= 1.49, 95%CI 0.79 to 2.82). Conclusions Compared with GnRHa, GnRHA requires shorter stimulation duration and less Gn, less affected the pregnancy rate, and reduces the incidence of OHSS. The use of GnRHA in clinical practice is relatively flexible with good acceptability. GnRHA for the superovulation IVF-ET offers an alternative treatment. The above conclusion still needs more well-designed, multi-center, and large-scale RCTs to confirm and update.