Orthopoxvirus vector has a broad prospect in recombinant vaccine research,but the rarely severe side-effect impedes its development.Vaccinia virus and Cowpox virus of Orthopoxvirus have broad host range,and they have typical host range genes as K1L,CP77 and C7L.These three genes affect host range of Vaccinia virus,disturb the cell signaling pathways,suppress immune response and are related to virulence.