[Objective] The aim of this study was to determine migration time of porcine embryos and to investigate the effects of embryo number on migration and spacing of porcine embryos. [Method] Migration and spacing of embryos were observed in gilts with one occluded oviduct and in those with one ovary. Their uteri were observed on Day 6, 7, 8, 9, 10, 11, 12, 13 and 15 of gestation, respectively. [Result] The embryos migrated from oviduct at one side to uterine horn at the other side. On Day 8 and 9, the embryos first migrated from one horn to the other horn. On Day 15, they could occupy the uterus completely. Migration rate and distribution of embryos were not affected by number of embryos, number of corpore lutea and uterine length. The uterine length was not different between on Day 6 and on Day 15. [Conclusion] The migration of porcine embryos occurs between Day 8 and Day 15 of pregnancy. Unilateral ovariotomy and ovariotomy do not affect embryonic growth and migration. [Objective] The aim of this study was to determine the migration of of porcine embryos and to investigate the effects of embryo number on migration and spacing of porcine embryos. [Method] Migration and spacing of embryos were observed in gilts with one occluded oviduct and in those with one ovary. Their uteri were observed on Day 6, 7, 8, 9, 10, 11, 12, 13 and 15 of gestation, respectively. [Result] The embryos migrated from oviduct at one side to uterine horn at the other On Day 8 and 9, the embryos first migrated from one horn to the other horn. On Day 15, they could occupy the uterus completely. Migration rate and distribution of embryos were not affected by number of embryos, number of corpore lutea and uterine length. The uterine length was not different between on 6 and on day 15. [Conclusion] The migration of porcine embryos occurs between Day 8 and Day 15 of pregnancy. Unilateral ovariotomy and ovariotomy do not affect embryonic growth and migration.