A reovirus, designated as CCRV-730, was isolated from channel catfish, Ictalurus punctatus, fingerlings suffering a severe hemorrhage in Hubei province in China. Experimental infection confirmed the pathogenicity of the virus and proved it to be the causative pathogen. Signs of the diseased channel catfish included abdominal distention, eyes bulging and hemorrhages of operculum, lower jaw, skin and fin bases. The CCK cell line was used for viral pathogen isolation. The electron microscopy observation of the virus infected cells revealed that there were a large number of reovirus-like particles measuring 60–70nm in diameter in cytoplasm arrayed in crystalline. The viral genomic RNA was extracted and analyzed by SDS-PAGE and the complete S-class (S7–S11) segments of genome RNA were cloned and sequenced. The sequence alignment analysis of the S-class segments of CCRV-730 with corresponding sequences of other Aquareovirus members in the genetic sequence database of NCBI indicated that the virus had high similarity to grass carp reovirus, especially shared 99%–100% nucleotide sequence identity with the grass carp reovirus 873 strain (GCRV-873). The results implied that the genetic variation of GCRV-873 potentially arose in natural environment and resulted in the viral host conversion or expansion and made it pathogenic to channel catfish.