Abstract: Three factors ,cytochalasin B （CB） pre-treatment,width of two electrodes and field strength of electric pulse （direct current）related to the parthenogenetic activation of rabbit eggs by electric stimulation were studied for nuclear transplantation. The results showed that the treatment of oocytes with 7.5 mg/L CB for 1 h followed by activation with electrical stimulation significantly improved the oocyte activation rate as compared with the oocytes without CB pre-treatment （79.4% vs 48. 1%，P＜0.05）. The activation rate of oocytes which were placed between the two electrodes with 0. 50mm apart was signifi-cantly improved as compared with the two electrodes with 0.25 or 1.00mm apart （79.4% vs 63. 1% or 35.0%,P＜0.05）. Furthermore,a high activation rate（90.9%）and develop-ment rate （47.5%） were achieved when oocytes were activated electrically with a field strength of 3.0 kV/cm（50μs） versus 1. 8,2.4,3.6 kV/cm.

Key words: Rabbit oocyte, Parthenogenetic activation, Electrical stimulation