Abstract: There were some Mule Muscovy ducks and the Taiwan White ducks,which was located in Fujian,Zhejiang,Anhui and Jiangsu Province in China,had the clinic symptoms with weak feet and low mortality rate since the second half of 2008.After the age of 40-day,the ducks were easily fracture,with nearly 30 percentage having the short beak infectious symptoms.About 60 percentage ducks had not reach the slaughter standards.The Muscovy ducklings immunized with the MDPV live actuated vaccine also had such infectious symptoms,typically like the MDPV infectious symptoms,causing greatly economic loss to the ducks farming industry.After the detection of new pathogen,virus isolation and the challenge experiments in Muscovy ducklings,we discovered that the new virus had many differences with the typical Muscovy duck parvovirus such as the genome,the host range and the pathogenicity.In conclusion,we suggested the newly infectious diseases named with new genotype Muscovy duck parvovirus,to avoid Muscovy duck origin parvovirus definition confusion.