This study was aimed at determining whether the epidemiology of PRRSV involved the hybrid wild boars.We conducted a serologic investigation of porcine reproductive and respiratory syndrome virus (PRRSV) in hybrid wild boar herds in China during 2008-2009.613 blood samples from Shandong Province were obtained from hybrid wild boars that had not been vaccinated against PRRSV.167 (27.2％) of 613 samples were seropositive for PRRSV,indicating that the prevalence of PRRSV differed between domestic pigs and hybrid wild boars in this area,and 2 PRRSV isolates (TAYZ and ZCYZ) were plaque-purified once in MARC-145 cells and amplified for sequencing and infection of other pigs.The result showed TAYZ and ZCYZ had higher nucleotide homologies in ORF5 with highly pathogenic PRRSV (prototype virus JXA1).