To investigate the effect of PMSG injection on the estrus, and the quality of embryos after mating and to determine the possibility of pig embryo freezing, two experiments were conducted. In experiment 1, sows or gilts were injected 1,000IU or 1,5001U of PMSG and measured interval to first estrus and duration of estrus, and after the mating the number of C. L. formed, the number of embryos collected, fertilization rate and pregnancy rate were investigated. In experiment 2, embryos were frozen using glycerol or DMSO as a cryoprotectant and survival rate and duration of survival were investigated. The results of these experiments indicated that by the injection of PMSG the interval to first estrus after weaning was reduced and the duration of estrus increased, while there was no significant difference in pregnancy rate between treatments. In addition the number of C. L. formed and the number of embryos collected increased by the PMSG injection, but the fertilization rate and the number of embryos transferable was most in 1,000IU of PMSG treated group. The recovery rate of embryos collected from sows mated following natural estrus was 74% and fertilization rate of them was 96%. Of 48 embryos frozen, 54.2% were survived after thawing and survival rate and duration of survival were better when DMSO was used as a cryoprotectant than glycerol was used.