Abstract: Antigenicity of the immune stimulating complexes in the outer membrane protein(OMP-ISCOMs) of Vibrio vulnifiticus was studied by injecting the vaccine into the European eels(Anguilla anguilla).The minimum dosage required for effective vaccination was determined by serology and immune protection test.The immune response was dosage dependent.Thirty days after the eels were challenged with the V.vulnificus FJ03-X2 strains at 200,100,50 and 25 μg·mL-1 to result in 100%,87.5%,75% and 50% of protection,respectively;and the titers of serum antibody of 1∶6400,1∶3200,1∶800 and 1∶200 in turn,respectively.It appeared that the minimum dose of the OMP-ISCOMs of Vibrio vulnifiticus vaccine was 0.59 μg·g-1.