Contagious ecthyma (also known as orf) is an acute skin zoonosis caused by orf virus (ORFV), which affects sheep, goats and humans. As one of the typical species of the Parapoxvirus genus of the Poxviridae family, orf virus has distinctive and unique characteristics of these species. A range of immuno-modulatory/pathogenesis -related genes acquired by virus that function is to limit (at least transiently) the effectiveness of host immunity during its evolution. This review is aimed to describe the latest progress on the molecular characteristics of ORFV, and upon which we analyzed molecular mechanism of the immune escape designed and a set of strategies developed for ORFV to effective against immune clearance of the host. Known as an essential component in evolutionary system, host is regulated by ORFV for using in population evolution. By the ORFV evolutional immune regulation components and its effect approach, we can understand the viral biological characteristics of ORFV, and it is helpful for us to further study the counter-measures of this disease.