〔Abstract〕 Objective To analyze the data related to the clinical outcome of preimplantation genetic testing(PGT) for double frozen, double biopsied blastocysts and double frozen, once biopsied blastocysts, in order to expand the existing data and provide some guidance for the clinical value and safety of PGT for frozen-thawed embryos. Methods Retrospective analysis was made on the 38 PGT cycles of frozen-thawed blastocysts. According to the frequency of biopsy, cases in the study were divided into two groups: double frozen, double biopsy(DFDB) group and double frozen, single biopsy(DFSB) group. The freezing method was vitrification. Results There were 24 patients in DFDB group, 34 blastocysts were not diagnosed in the last PGT cycle, 32 blastocysts survived after thawing, and the survival rate of thawed blastocysts was 94.12%. After the second biopsy of these 32 blastocysts, genetic testing was performed, and all of them were definitely diagnosed, including 15 normal blastocysts(46.88%) and 17 abnormal blastocysts(53.13%).There were 14 patients in DFSB.The remaining 50 blastocysts in the last ICSI cycle were thawed and all blastocysts survived after thawing. Biopsy of these 50 blastocysts and genetic analysis showed that 47 blastocysts were diagnosed, including 9 normal blastocysts(18.00%), 28 abnormal blastocysts(56.00%), 10 mosaic blastocysts(20.00%), and 3 undiagnosed blastocysts(6.00%). In DFDB group and DFSB group, 8 patients and 5 patients transferred the normal blastocystswhich all survivedafter thawing. There were 5 clinical pregnancies and 3 clinical pregnancies, respectively. One healthy live birth was obtained respectively in each group. Conclusion Acceptable pregnancy rate can be obtained whatever DFSB or DFDB blastocyst, which is of clinical value.However, due to the small sample size, we need to expand the sample size to further explore its safety.