Objective To explore the relevant parameters and clinical outcome of frozen-thawed blastocyst transfer compared with fresh blastocyst transfer. Methods A historic cohort study was conducted to analyze the blastocyst implantation rate and clinical pregnancy rate of 61 patients receiving fresh blastocyst transfer and 372 receiving frozen-thawed blastocyst transfer from Mar. 2015 to Dec. 2016 in Changhai Hospital of Second Military Medical University. And then the clinical outcomes of day five (n=308) or day six (n=64) embryo were analyzed in the frozen-thawed blastocyst transfer group. Results There was no significant difference in age or number of the transferred blastocysts between the two groups. Blastocyst implantation rate in frozen-thawed blastocyst transfer group was significantly higher than that in fresh blastocyst transfer group (40.2% vs 29.6%, P=0.036), while no significant difference was found in clinical pregnancy rate between the two groups (57.8% vs 47.5%, P=0.134). Blastocyst implantation rate and clinical pregnancy rate of day five embryo were significantly higher than those of day six (42.3% vs 30.1%, P=0.016, and 60.7% vs 43.8%, P=0.012, respectively). Conclusion The pregnancy outcome of frozen-thawed blastocyst transfer is better compared with fresh blastocyst transfer, especially when transferring on day five.