Abstract:Newcastle disease virus (NDV) is a member of the genus Avulavirus in the family Paramyxoviridae. The genome of NDV is a non-segmented， single-stranded， negative-sense RNA. Therefore， the frequency of genomic variation is relatively high due to the inherent error rate of the RNA polymerase-dependent RNA replication， which is the main driving force for virus evolution. Additionally， the multiple host range for NDV and frequent vaccination for the control of ND also promote the NDV evolution. During the evolution， NDV has generated variants of multigenotypes and subgenotypes， resulting in expanded host range， virulence diversity and antigenic variations.