In most cases, cryopreservation is performed when an “extra” embryo after a regular IVF cycle. “Fresh” transfer is usually preferred. However, some doctors recommend selective frozen embryos. This transfer is also identified as an “all frozen” method. In this case, all embryos are cryopreserved and transferred in the FET cycle around the next month. The scientific value of cryopreservation of embryos has progressively increased over the decades due to technological advances inability to freeze embryos in the cleavage stage and blastocyst stage. The first success of cryopreservation is achieved through slow freezing, which has been the preferred method for cryopreservation of embryos for the past two decades. Recently, the optimization of the verification method, the use of cryoprotectants and rapid freezing, has become more widely used. If implemented correctly, vitrified embryos after thawing have excellent survival. A number of vitrified reports show a ninety-five percent survival rate. In addition, vitrification of embryos was assessed by clinical results shows that CPRs is Compared with slow freezing embryos, the vitrification group in the vitrification group was 50% higher, and similar results were seen in the ongoing pregnancy and implantation rates.