This study was carried out to clarify the effects of various kinds of cryoprotectants which were frequently used in freezing embryos of domestic animals on the survival of frozen-thawed mouse embryos. Mouse embryos were collected by hyperstimulation induction of ICR mouse. The samples were slowly cooled ($l^{circ}C/min$) to temperatures between $-7^{circ}C$ and $-30^{circ}C$ before direct transfer to liquid nitrogen ($-196^{circ}C$) and thawed rapidly ($-500^{circ}C$/min). As cryoprotectants, Glycerol, DMSO, Ethylene glycol and Propylene glycol were used and applied each 2 cell, 8 cell, morula in embryo stage. After normal mouse embryos developed to blastocyst by in vitro culture, we observed recovery rate and developing rate of embryos at thawing. The results obtained in these experiments were as follows : 1. The in vitro development rate from the frozen-thawed 2 cell embryos to the blastocyst were 67.7% in ethylene glycol, 65.7% in Propylene glycol, 55.2% in glycerol and 50.0% in DMSO respectively. 2. The in vitro development rate from the frozen-thawed 8 cell embryos to the blastocyst were 83.6% in DMSO, 75.7% in glycerol, 52.2% in propylene glycol respectively. 3. The in vitro development rate from the frozen-thawed morula to the blastocyst were 84.2% in glycerol, 80.0% in DMSO, 66.6% in propylene glycol and 55.2% in ethylene glycol respectively.