gene from infectious spleen and kidney necrosis virus (ISKNV) isolated from mandarinfish,, was amplified by PCR, and then cloned into the prokaryotic expression plasmid pET32a(+). The recombinant 093 protein expression was induced by IPTG and purified by Ni-NTA affinity chromatograph. Polyclonal antibodies were raised in rabbits against the purified protein and the reaction of the antibody was confirmed by western blotting using the purified protein and the spleen and kidney of healthy and diseased mandarin fish. The immunogenicity of 093 protein was investigated by neutralization test and immune protection test. The results showed that the recombinant 093 protein was found as the inclusion bodies in . Western blotting of rabbit sera against recombinant 093 protein and the spleen and kidney of diseased mandarin fish showed a protein recognition. The antiserum could neutralize ISKNV infection and could provide fish 10-days-long 100% protection. The recombinant 093 protein could protect mandarinfish against virulent challenge with ISKNV and the average RPS of 093 group was 45.3%. The results indicated that the recombinant 093 protein had It could be a potential vaccine candidate and antigen candidate for antiserum treatment.