Abstract: The Physicochemical Characteristics and Pathogenicity of five PRRSV strains including two European types PRRSV and three North American types PRRSV were studied, which were isolated from pig farms in Fujian province. The results showed that all the five PRRSV strains could induce regular cytopathogenic effects (CPE) on Marc-145 cells, but CPE was not appeared on PK-15,Vero,CEF or MDEF cells after three times of blind passages. The five PRRSV strains showed the same sensitive to acid, pH value 3, chloroform and trypsin, but different to the temperature. Compared with the North American types PRRSV, the European types PRRSV were more resistant to pH value 9.It was confirmed that the European type PRRSV-FJ0602 has a low pathogenicity to pigs but the North American type PRRSV-FJ0604 has a high pathogenicity to pigs according to the animal experiment.