To observe the replication dynamics of PCV2 in PK15 cell, PCV2–1B infectious clone virus was inoculated to the homogenous PK15(A10) cells. After grew to 100% confluence, the cell was serially passaged. And part of the 5th and 6th -generation cells were maintained by altering cell culture medium at one day interval to maintain the cells. The culture medium of the 10th generation cells was inoculated to fresh A10 cells which was also maintained by culture medium alteration. The results of PCR and quantitative PCR showed that after infection, the PCV2 genome copies increased with the growth of the cells until the cell reached 100% confluence. And the PCV2 genome copies maintained at a level of 107–108 copies/mL in cells after maintained by culture medium alteration for 10 days. Infection of A10 cell with culture medium of the 10th generation cells also showed the virus genome content increased with the growth of the cell, and when reached 108 copies/mL, the genome copies maintained at 107–108 copies/mL.