Abstract:White spot syndrome virus(WSSV) caused serious disease and economic losses in the world, becoming a limiting factor in sustainable devolpment of shrimp industry.Shrimp cell culture is a simple and rapid tool to study the pathogenic mechanism of the virus and to determine the viral susceptibility to the cells.In this research, primary culture cell from lymphoid organ of greasyback shrimp(Metapenaeus ensis) has been established by using an improved 1.5×L-15 cell culture medium.The cell cytopathic effects(CPE) were observed, as the primary cell monolayer inoculated with WSSV.The results showed that the migration of lymphoid cells from the explants was initiated at 3 h after seeding, and a 80% confluent cell monolayer was formed within 24-36 h and remained viable for over 20 days.Within 24 h post inoculation, apparent CPE was observed in the primary culture cells.The infected cells initially exhibited shrinkage or became aggregated, while the network structure between the cells disappeared.Finally, the most infected cells rounded up and then detached from the culture dishes.Under fluorescence microscope, Hoechst 33342 staining showed that the nuclei of lymphoid cell enlarged and deformed with a deeper color, 48 h after inoculation with WSSV.Under electron microscope, a large number of clustered viral particles were founded in the affected nuclei, while the organelles were pushed to the cell edge, and the outlines of the cell membranes were vague.The study illustrated that the cultured lymphoid cells had apparent CPE as inoculated with WSSV.This phenomenon proved that WSSV could infect and multiply within the primary culture cells.