This experiment was conducted to determine the effective method for transfer of embryos in mature rats. Total number of 941 ova were recovered from 115 donors and 327 embryos of morula to late blastocyst stage were transferred surgically to 52 recipients (3 to 12 embryos per recipient). The results obtained were summarized as follows: 1. Pregnancy rate after embryo transfer was significantly (p$lt;0.05) lower in embryos from superovulated rats (37.5%) than control rats (60%). Weight of young at birth and gestation period were not significantly different between the groups of recipient transferred with embryos from control and superovulated rats. 2. Pregnancy rates after transfer with cell stage of embryos (50% in morula vs 45% in blastocyst) were not significantly different. 3. Pregnancy rates after transfer with degree of synchronization were 62% in -24 hrs. 50% in D hrs, and 0% in +24 hrs., respectively. And gestation period with degree of synchronization were not significantly different. 4. Pregnancy rates with number of embryos transferred to recipients (3-5, 6-8 and 9-12) were significantly (p$lt;0.05) higher when 9-12 embryos transferred (63%) than 3-5 or 6-8 of embryos transferred (50% and 36%). Pregnancy rates after transfer were not affected by progesterone priming.