In recent years, the major viral diseases of cultured marine fish are iridovirus and nodavirus infections, which have caused severe economical lose of aquaculture. At present, development of a formalin-killed bivalent virus vaccine is a good choice to control these diseases. In the present project, we will select a high viralent and antigenic virus as a seed for bivalent vaccine, accomplish the efficacy and safety tests and proceed to a preliminary field trial. Thus, the result can provide a control method for the above viral diseases, lower the economical lost and increase the value of our products.