Abstract: 【Objiective】Various viruses were detected from tissue samples of porcine high fever syndrome. Etiology of porcine high fever syndrome and molecule epidemiology of porcine reproductive and respiratory syndrome virus were determined. 【Method】PRRSV North America type and Europe type, porcine circovirusⅡ, porcine haemagglutinating encephalomyelitis virus, Japanese encephalitis virus and Pestivirus were identified by (RT-)PCR from tissue samples. Sequence of PRRSV ORF5 was amplified and analyzed. 【Result】16 PRRSV North America type positive samples and PCV2 positive samples were detected; other viruses were not detected. Sequence analysis of PRRSV ORF5 indicated: PRRSV isolated strains could be divided into two groups. 【Conclusion】1）PRRSV was the causative agent of porcine high fever syndrome in China. 2) PRRSV prevalence strain was strain represented by JX0612, however defferent genetic characteristics PRRSV strains also spread in China.

Key words: Porcine high fever syndromeHigh pathogenicity porcine reproductive and respiratory syndrome virus, ORF5, Molecule epidemiologyGenetic evolution analysis