This study was carried out to investigate the effects of cell stage, equilibration time, precoolmg, straw loading and dilution method on the post-thaw survival of intact, ZP-free or bisected mouse embryos. When embryos were vitrificated at two-step dilution in double columns following equilibration for 10 minutes. the significantly(P$lt;0.01) higher post-thaw survival rates were obtained with 8-cell embryos(91.3%) or morula (89.3%) than blastocysts(74.6%). Loading of morula in straws with double Medium-2 columns improved significantly(P$lt;0.01) their post-thaw survival rates(81.30%), compared with single Medium-2 columns(70.0%). Any significant effects on the post-thaw survival rate of embryos were not observed between the dilution methods and temperatures of Medium-2. The post-thaw survival rate of ZP-free or bisected embryos cryopreserved by the present vitrification was resulted in 73.5 and 68.8%, respectively.