Betanodavirus infection causes viral nervous necrosis in many fish worldwide.It is commonly accepted that the virus-like particles(VLPs) are effective vaccines against betanodavirus.Here,the three-dimensional structure of orange-spotted grouper nervous necrosis virus(OGNNV) VLP at 3.9(A) reveals the organization of capsid proteins(CPs).Based on the structural results,seven putative sites were selected for the foreign peptides insertion.The results demonstrate that loop 210-220 and C-terminus of CP are the ideal sites to accommodate short foreign peptides for presenting potential biotechnological applications such as multivalent vaccines and viral vectors.