The aim of this study was to screen preparation method of Photobacterium damselae subsp. piscicida vaccine for cobia (Rachycentron canadum). Various candidate vaccines combined with inactivated bacteria, extracellular products and Freund’s adjuvant were involved to assay their efficiency against photobacteriosis by the antibody response. The results showed that the best candidate vaccine were found that was an admixture of inactivated bacteria of 8.4×109-1.7×1010 cells/fish (p<0.05) and Freund’s adjuvant which produced high antibody titter of 1:416-1:960 during 29-35 days post-vaccination, and their safety doses for intraperitoneally vaccinated cobia were 0.1-0.6 ml/fish.