To evaluate the effect of trial transfer on embryo transfer.Embryo transfer guided by ultrasound was performed in 114 cycles. And trial transfer was accomplished in 101 of them prior to embryo transfer. The clinical pregnancy rate and embryo implantation rate were compared between the group with trial transfer and the group without, and also among the sub-groups formed according to the difference between the trial transfer position and the actual embryo depth.There was no statistically significant difference in the clinical pregnancy rate and embryo implantation rate between the group with trial transfer and that without trial transfer(59.41% vs 61.54%, 35.81% vs 31.43%, P > 0.05), nor was there between the two subgroups of the group with trial transfer (61.54% vs 58.67%, 40.79% vs 34.09%, P > 0.05).As far as modern embryo transfer techniques are concerned, trial transfer can not provide accurate guidance for the depth of embryo transfer.