Abstract: Objective: To investigate the developmental potential of mouse somatic nuclear transfer embryos （SCNT） with different treatment of donor cell. Methods：Two methods, the intact cell and the naked nuclei injection，were used to produce cloned embryos. The reconstructed embryos and IVF control embryos were transferred into receptors′ uterine cavity. The rates of activation，cleavage，blastocyst of reconstructed embryos and in vivo developmental outcomes were compared. Results：The rate of cleavage and blastocyst in the intact cell group was significantly lower than that in the bare nucleus group （χ2cleavage=5.785，P=0.016；χ2blastocyst=6.092，P=0.014）. There were significantly difference in the weight of fetus in three groups F=14.331，P=0.00），the intact group had the heaviest wet weight of fetus. The weights of placental in the bare nuclear group and the IVF group were significantly lower than that in the intact cell group （compared with the normal group，t=-8.786，P=0.00；compared with bare nuclear group，t=-6.573，P=0.00）. Conclusions：The developmental potential of mouse somatic cell nuclear transfer embryos could be improved by the bare nucleus injection.

Key words: Nuclear transfer techniques, Genetic techniques, Cleavage stage, ovum, Blastula, Embryonic development