Visualization of the pronuclei and survival rates of microinjected pronuleate embryos produced from matured and fertilized in vitro were examined in the pig. In vitro matured follicular oocyte, in TCM 199+20% FCS were fertilized in nitre with epididymal spermatozoa in mTALP + 15㎎/㎖ BSA after 1 h capacitation. At 18 h post-IVF (hpi), putative zygotes were centrifuged at 15,000 rpm in an Eppendorf tube for 0 (control), (1.5, 2.5 and 10 min, respectively. Subsequently developmental capacities of the centrifuged zygotes and DNA-injected zygotes were examined. As the duration of centrifugation increased clearer dislocation of dark cytoplasm was obtained. The cleavage rates of the centrifuged zygotes at 48 hpi were 82, 7.3, 73, 67 and 59% in 0 (control), 0.5, 2, 5 and l0 min, respectively. And further development to $gt; 3-cell at 120 hpi were 40, 44, 44, 36 and 22% in 0. 0.5, 2, 5 and 10 min, respectively. Centrifugation for 5 min was chosen for clear visualization and better survival for subsequent experiments. Cleavage rates of the microinjected zygotes were 80, 57 and 55% in control centrifugation alone, pricking alone and DNA-injection groups, respectively. Further developmental rates to ≥3-cell at 120 h were 50, 22 and 21% in control centrifugation alone, pricking alone and DNA-injection groups. These results indicate that the centrifugation for 5 min would be sufficient for the visualization of pronuclei and better survival of pronucleate embryos after DNA microinjection. Thus the DNA injection system in porcine embryo should b~e used for the production of transgenic livestock animals.