Disruption of myostatin (MSTN) gene in pigs may improve porcine lean meat percentage (LMP), and create an animal model for certain human diseases. Using zinc-finger nucleases (ZFNs) technology, MSTN gene was deleted in Wuzhishan miniature pig fibroblasts by transfection of either ZFNs plasmids or ZFNs mRNA in high efficiency. Strikingly, ZFNs encoding mRNA could produce MSTN+/-and MSTN-/- cell colonies with single or double allele deletion by single transfection. Sequencing results demonstrated that 92.18% of the mutations were short fragment deletions or insertions (≤10 bp). Prediction of amino acids sequences indicated that more than half of the mutations cause premature transla-tional-termination codon. MSTN+/+, MSTN+/-, and MSTN-/- cell colonies were used as nuclear donor for somatic cell nuclear transfer (SCNT), and developmental potential of SCNT embryos were measured by the blastocyst rate. The results revealed no significant difference in development competence among the three kinds of reconstructed embryos (14.29% vs. 19.64% vs. 16.13%), which provides the possibility of making myostatin knock out pigs in the future.