relationship between transmission routes of AVNV and mesoplankton and microplankton in the ocean for culturing scallops. Plankton samples were collected in Liuqinghe Qingdao and Sanggou Bay, Rongcheng, from April to November 2009. In August, the AVNV copy number carried by plankton was identified by FQ-PCR. Results showed that plankton samples from both ocean areas carried the virus, and that the virus numbers differed with different particle sizes. Plankton samples with the same particle sizes at the Liuqinghe site carried more AVNV copy numbers than those at the Sanggou Bay site at a given time. Plankton particle sizes smaller than 200 mesh carried the greatest amount of viruses (viral DNA number reached 9.45×10⁶ copy/mg DNA), followed by plankton particle sizes between 60−200 mesh size. Plankton particle sizes larger than 60 mesh carried the least amount viruses. Finally, results suggest that plankton can carry AVNV, and that they may be an important host of AVNV.