) were collected from Huzhou, Zhejiang Province. After filtration treatment, the tissue suspension was inoculated in CIK ce1ls, but no obvious cytopathic effects (CPE) were observed even after passages of eight times. However, plenty of nonenveloped virus particles with subsphaeroidal shape were observed under electron microscope (EM), which was highly similar to reported grass carp reovirus (GCRV). The nucleic acid of purified virus was digested by DNases, RNases and Mung-bean Nuclease respectively. The results showed the nucletic acid of the virus was double-stranded RNA, and the SDS-PAGE electropherosis further suggested the virus possessed 11 segments of dsRNA, which was the typical characteristic of GCRV. In order to classify the strain on the molecular level, the complete nucleotide sequence of S6 was determined. The S6 comprised 2 030 nt and was predicted to encode a 68.4 kD protein. The result of cluster analysis revealed that the new isolate was a member of aquareovirus, but identity between it and representative strain GCRV873 was 33%. The deduced amino acid sequence shared highest identity (33%) with grass carp reovirus 873 strain, indicating that the new isolate was presumed to be a new type ofGCRV.