Vibrio harveyi, the major causative agent of vibriosis, affects a diverse range of marine cultured organisms over a wide geographical area. However, reports about screening the effective antigen and research on vaccines of V. harveyi are scarce. Flagellin, lipopolysaccharide (LPS) and outer membrane proteins (OMP) are major immunogenic antigens in many Gram-negative bacteria. In this study, the flagellin, OMP and LPS of the V. harveyi TS-628 strain isolated from infected groupers were extracted and Western blot analysis was used to detect the antigenicity of these extractions. Results of the Western blot assay reveal that there are four positive flagellin bands: 35 kDa, 38 kDa, 43 kDa, and 52 kDa, of which the 43 kDa and 52 kDa bands displayed the strongest positive reaction. There are five positive OMP bands about 35 kDa, 38 kDa, 43 kDa, 47 kDa, and 52 kDa, of which the 43 kDa appeared to have the strongest positive reaction although the other four proteins also displayed strong reactions. However, LPS is Western blot-negative. These results indicate that the 43 kDa and 52 kDa flagellin and OMP of size 43 kDa, 52 kDa can be candidates for developing vaccines against V. harveyi.