Objective To verify the quality as well as in vitro and in vivo development potentiality of mousedormant embryos after freezing and thawing, and provide a reference for the production and application of embryonicdormancy technology. Methods Normally incubated and dormant embryos were frozen by conventional freezing method,followed by in vitro resuscitation culture and embryo transfer experiments. Subsequently, the cells of dormant and normallyhatched embryos before and after freezing and thawing were counted by double immunofluorescence staining, and thequalities of the two embryo types before and after freezing and thawing were observed. Results The recovery rate fromfreezing and thawing and the development rate of dormant embryos were significantly higher than those of hatched embryos(72. 1% vs 50. 2%, P < 0. 01; 94. 2% vs 73. 9%, P < 0. 01). The pregnancy rate of dormant embryos was significantlyhigher than that of hatched embryos (40. 8% vs 30. 1%, P < 0. 05). The number of cells in the inner cell mass of thedormant embryo was significantly higher than that in the hatched stage (27. 83 vs 19. 53, P < 0. 05), while the differencein the number of trophoblasts was not significant. The number of inner cell clusters in the dormant embryos after freezingand thawing was significantly higher than that in the hatched embryos (25. 18 vs 14. 68, P < 0. 05; 114. 09 vs 73. 88, P <0. 05). Conclusions The embryo quality as well as in vitro and in vivo development potential of mouse dormant embryos after freezing and thawing are better than those of normally hatched embryos.