This study evaluated the effect of dietary administration Lactobacillus brevis MF01 on hematology parameters and survival in S. luciperca after exposure to Aeromonas hydrophila. The fed fish with dietary administration containing A1 (L.brevisMF01 10¹⁰ CFU/ g), A2 (L. brevis MF011⁸CFU/ g) and the control group (without Lactobacillus) were investigated for 45 days. At the end of the feeding period, the fish were take blood and then were challenged with 4.5× 10⁸CFU/ml A. hydrophila. Fish were monitored daily and rate of survival was recorded over a period of 7 days post challenge. The hematology results showed that feeding with supplemented L. brevis (10⁸, 10¹⁰cfug^-1) and control group had no significant difference. After being exposed to A. hydrophila, the lymphocytes in the probiotic treatments were higher than the control group and the neutrophils in injected control group were significantly higher than probiotic groups. The survival rate, after exposure of the probiotic treatments, were higher than that in the injected control group.