Abstract: 【Objective】 To study the effect of sheep myostatin propeptide on myoblast differentiation. 【Method】 Myostatin cDNA Lentivirus vector plasmid was constructed and expressed in C2C12 cell and the ability of myostatin prepeptide to infect C2C12 cells was studied. 【Result】 The LV-CMV -GFP infection group showed obvious long strips of myotubes, while LV-CMV-MSTN-flag-GFP group saw only a small amount of myotubes formed. To further determine the differentiation of myoblasts, myotube fusion rate was determined. The myotube fusion rates of were 5.53%, 6.62% and 9.38% respectively in the untreated group, the control group and the test group. The fusion rate of myotubes in the test group was significantly higher than that in the control group and the untreated group (P<0.05). 【Conclusion】 The overexpression of Myostatin pro-peptide gene inhibited the expression of Myostatin gene, thus affecting the formation of myotubes and inhibiting the process of differentiation.