Mortality in vaccination fish for 5 days Aeromonas hydrophila liposome vaccine at dose 1*109 bacteria/fish/day pound (2.1, 2.2) and unvaccinated fish pound (2.5, 2.6) was challenged by intramuscular injection with A. hydrophila at 3*108 CFU/fish, Mortality in vaccination fish for 5 days Aeromonas hydrophila liposome vaccine at dose 1*109 bacteria/fish/day pound(2.3,2.4) and unvaccinated fish pound (2.7, 2.8) was challenged by intramuscular injection with A. hydrophila at 3×107 CFU /fish. *Significant difference between vaccinated and control at level (p≤0.05).