Abstract: According to the published VIR gene sequence of ORFV（Strain NZ2）in the GenBank,one pair of primers were designed and synthesized.VIR gene of ORFV（OV/nm-05）of Inner Mongolia isolate were specially amplified by PCR method and then cloned into pEASY-T1 vector.The sequences of VIR gene of this virus were obtained after sequencing.The sequencing analysis showed that the homology between OV/nm-05 strain and 1710/03 strain was the highest,being 98.0%.And the homology between OV/nm-05 strain and 513/04 strain was the lowest,being 95.4%.The results demonstrated that there was a little variation between VIR gene of Inner Mongolia isolate of contagious ecthyma virus of sheep and other reference strains,which laid the foundation for further understanding the structure and function of VIR gene from the perspective of molecular biology.