These experiments were performed to develope a simple and reliable method of bovine embryo transfer under the field conditions. Of 42 synchronous (+12 hours) recipients, 37 and 5 were received single fresh and frozen embryo, respectively, by nonsurgical method. The results obtained in these experiments were summarized as follows: 1. Of 42 embryos transferred non-surgically, 20(47.6%) survived for more than 45 days after transfer. 2. Ten healthy calves (28.6%) were produced from 35 recipients which received single embryo, respectively. 3. Of 5 frozen embryos imported from Japan, and transferred non-surgically 3 developed to calving normally. 4. Embryos were transferred to recipients in estrus 12 hours later than donor (+12), the same time (0) or 12 hours earlier than donor (-12). The 0 group showed significantly higher (p$lt;0.05) calving rate (33.3%) than +12 group (25.0%) or -12 group (25.0%). 5. Calving rates of blastocyst (31.3%) or hatched blastocyst (30.0%) were significantly (p$lt;0.05) higher than that of morula (22.2%).