Abstract: The objective of the prensent study was to reserch molecular biology and nosogenesis of porcine circovirus, isolate porcine circovirus from pigs and then identify these strains by specific PCR assay. In this experiment spleen and lymph of swine were treated with trypsinase, then inoculated on pk-15 cells line and adapted tocell lines.540 bp gene of ORF2 segment was applified by PCR technology from pk-15 cell. characteristic PCV fluorescence was discovered in fluorescence microscope by IFA( indrect fluorescent antibody )technique, it was showed that strain was infectious. Purified virus was observed by Electron microscopic，we finded the average size of the isolated virus was 70~80 nm，rotundity ,without viral envelope. The result showed that isolated virus was porcine circovirus.