Provided is a method of effectively producing a cloned animal by demecolcine treatment. A conventional method of producing a nuclear transfer embryo of an animal further includes demecolcine treatment after activation of a fused oocyte. Moreover, the method of producing a cloned animal is characterized by culturing the nuclear transfer embryo in vitro and transferring the embryo in vivo. This method significantly improves in vitro development of somatic cell nuclear transfer embryos and maintenance of pregnancy from transfer of somatic cell nuclear transfer embryos in a surrogate mother up to delivery.