Somatic cell nuclear transfer is an efficient technique for the multiplication of elite livestock, engineering of transgenic animals, cell therapy and xenotransplantation, and analyzing the interactions between nucleus and cytoplasm, for various agricultural, biomedical and research purposes. Since the first somatic cell clone lamb was born, tremendous progress has been made toward developing technology for animal cloning. Viable farm animals and mice have now been produced by nuclear transfer using various fetal and adult somatic cells as nuclei donors. Transgenic clones were also produced from nuclear transfer of transfected somatic cells. In the future, somatic cell nuclear transfer will provide more numerous opportunities, both in basic and appled research as well as immediate uses in the generations of superior clone and transgenic animals. However, further technology refinement and improved understanding of the process are essential for commercial and basic research applications.