Abstract: The aim of the study was to explore the best united activation method of bovine somatic cell nuclear transplantation. Enucleated oocytes matured in vitro for 22-24 hours were taken as the recipient cytoplasts, the fibroblasts from bovine ears were taken as donor cells and were inserted into the perivitelline space of the enucleated oocyte to form the reconstructed couplet. The combined chemical activation methods were compared under the condition of electrical filed strength 25N/C, pulse width 10 μs, pulse number 2 times. The results showed that the best chemical activation was 6- DMAP + CB whose rates of cleavage (74.1% ) and blastula (27.8%) were higher than those of other groups. The fusion rate of 6-DMAP+CB was the highest but was not significantly different compared with that of other groups. The optimal condition for fusion and activation of the bovine somatic cell nuclear transfer was obtained preliminarily and would make foundation for somatic nuclear transplantation in the future.