Abstract: Ovine sperm extract (OSE) was used to activate ovine somatic cell nuclear transfer (SCNT)embryos and goat-ovine interspecies somatic cell nuclear transfer(ISCNT) embryos. The effects of different dose of OSE activation on the development capacity of the reconstructed embryos were compared according to the cleavage rate, blastocyst rate and blastocyst cell number. The results showed that OSE could effectively activate the SCNT and the ISCNT embryos and the optium concentration of OSE was 5 mg/mL, the activation effect was significantly（P<0.05） better than other groups. The effects of OSE activation or chemical activation (using ionmicin and 6-DMAP) on the development capacity of the reconstructed embryos were evaluated, the results indicated that there was no significant difference in blastocyst rate and blastocyst cell number when the ISCNT embryos were activated by using the OSE or the chemical activation method and there was no significant difference in blastocyst rate when the SCNT embryos were activated, however, there was a significant increase（P<0.05） in blastocyst cell number when the SCNT embryos was activated by using OSE compared with the chemical activation method（72.4 vs 65.2 ,P<0.05）.