Abstract: By means of the serial nuclear transplantation technique, the authors obtained an nuclear transplant fish from subcultured cell originated from the blastula cells of the crucian carp (Carassius auratus L.). This nuclear transplant fish survived for three years, but its sexual glands were undifferentiated. The authors have also abtained an sexually mature adult fish from short-term cultured kidney cell nucleus of an adult crucian carp.Results of the experiment implied that the subcultured cell nuclei of fish blastula cells and the specialized somatic cell nuclei of adult fish still retained their developmental totipotency, and thus, it indicated that there is a possibility of fish somatic cell breeding through the use of the nuclear transplantation.