Abstract: Materials about incidence of swine high fever syndrome were gained by epidemiological investigation of parts of Jinlin and Liaoning province. Porcine reproductive and respiratory syndrome virus, paramyxovirus virus and swine fever virus were mainly detected by electron microscope ; Serum testing swine high fever syndrome major pathogen antibody negative health piglets inoculated with paramyxovirus virus, virus solution, inactivated vaccine isolated from tissue samples in Jinlin province,meanwhile a negative control was made. Detection methods were used to study the clinical infection piglets including pathological testing, virus isolation, bacterial Detection. Pathogenic characteristics, morbidity regularity of swine high fever syndrome have been discussed as well as antibody dependent enhancement(ADE) which was taken place in the employment of inactivated vaccine. The results showed that: PRRSV was the major pathogen of swine high fever syndrome in the two provinces preliminarily and antibody dependent enhancement(ADE) phenomenon was concomitanted in the apply of inactivated vaccine.

Key words: swine fever unknown; porcine reproductive and respiratory syndrome virus; paramyxovirus virus; swine fever virus; antibody dependent enhancement(ADE)