This study was carried out to obtain the basic information on splitting and culture of mouse and bovine embryos. Two-, four-, eight-, cell and morula mouse embryos were digested with pronase, splitted in vitro by micro-glass needel with hand, and bovine embryos were splitted by micromanipulator. The splitted embryos were cultured under 5% of CO2 gas in air at 37$^{circ}C$ for 48-72 hours. The results obtained in this study were summarized as follows: 1. The mouse and cattle were superovulated by 5IU of PMS and HCG, and 2500IU of PMS and 25mg of PGF2$alpha$, respectively. The average number of embryos after superovulation were 32.5$pm$8.2 and 7.5$pm$3:1, respectively. 2. Out of total 122 embryos splitted, the successful splitting rate was 75.0%, 66.7%, 68.4% and 71.4% in 2-, 4-, 8- and morula embryos in mouse, respectively. There was no different splitting rate between mouse(71.4%) and bovine embryos(66.7%) in morula. 3. The successful culture rate of splitted embryos was 68.0% and 67.9% in mouse and bovine embryos, respectively.