Porcine circoviruses(PCV) are the smallest nonenveloped DNA viruses containing a unique single-stranded circular genome. No recognized link was found between PCV infection of pig and disease. But the PCV consistently identified from postweaning multisystemic wasting syndrome(PMWS) and researches indicate that there are strong relationships between PCV and PMWS. Clinical signs were emaciation, dyspnea, high fever with normal appetite. Necropsy findings showed respiratory disease complex lesion and lymph node anomalities. An indirect-immunofluorescent antibody procedure was used to assay swine sera for the presence of PCV atibodies. Antibodies against PCV were found in an average of 20% of the samples tested. The PCV DNA was amplified from lymph nodes collected from pigs. PCV specific primers were successfully amplified PCV DNAs. Further studies are needed to determine the possible role this virus might have in disease.