Abstract:A pair of primers were designed and synthesized based on the sequences of the ARV and MDRV S3 genes,the S3 gene segment of the novel NP03 duck reovirus isolate could be specifically amplified by RT-PCR and be conducted sequence analysis. Virion RNA was isolated by treatment of aliquots of the virus with LS TRIAZOL. The cDNA of the S3 gene frame of J03 was amplified by reverse transcription-polymerase chain reaction ,cloned into pMDT-18 vector and sequenced,respectively.The results show that the cloned S3 gene includes the complete open reading frame (ORF).Evolution analysis demonstrated that the S3 nucleotide sequence from isolate J03 shares 60%~60.2%identity with chicken isolates, 61.9%identity with a turkey reovirus and 58.2%~62.7%identity with muscovy duck reoviruses,and 68.2%~69%,68.2%,63%~70.4%amino acid sequence identities with chicken isolates, a turkey reovirus, muscovy duck reoviruses,respectively.The results indicate that J03 is a novel duck reovirus is different from ARV and MDRV.