Originally described from Japan, Cyprinid herpesvirus 2 (CyHV-2) was present in at least five other countries and probably has a global distribution in goldfish ( Carassius auratus ).Up to now,CyHV-2 has drawn little attention and is rarely reported in China.Recently,silver prussian carp ( Carassius auratus gibelio ) farmed in Yancheng,Jiangsu Province,was reported by news to be infected by CyHV-2 and caused heavy economic losses.But little was known about the ways of virus transmission,potential reservoirs and sources of infection for this newly emerged virus.Goldfish can be a source of infection by carrying CyHV-2 but showing no clinical symptom.To understand the epidemiology of CyHV-2 in China,healthy goldfish from markets in different districts were tested for CyHV-2 by degenerate polymerase chain reaction of the viral polymerase gene followed by sequencing.Results demonstrated that CyHV-2 has a wide geographic distribution in China.Molecular study indicated that the sequences of DNA polymerase encoded by CyHV-2 isolated from goldfish in China were identical with the published sequence for CyHV-2.The helicase sequences of CyHV-2 from goldfish were also partially identical with those from silver prussian carp cultured in China,suggesting that the virus carried by goldfish and silver prussian carp were the same.Between the isolates from goldfish and H.Fukuda from Japan,there was only one or two residues difference in the amino acid sequence of helicase or intercapsomeric triplex protein,suggesting that the two isolates of CyHV-2 were highly similar,but not the same.