The current study evaluated effects of dietary administration doses of Entrococcus faecium on the hematological factors, and disease resistance of Sander lucioperca against Aeromonas hydrophila infection. Fish were fed with dietary administration containing E. faecium doses including of (10¹⁰, 10⁸CFU/ g) for diet A₁ and A₂, respectively in a commercial diet as basal diet were used for 6 weeks. The control group was basal diet with serum. The hematological and immunity parameters were measured and fish were challenged with A.hydrophila (4.5×10⁸CFU/mL). Fish were monitored daily and the mortality rates were recorded over 8 days post – challenge. The results indicated that HCT in A₁ treatment (10¹⁰CFU/g) had significantly increased in compare to the control and A₂ (10⁸ CFU/g) treatments (p<0.05).  MCV in A₁(10 ¹⁰CFU/g) and control groups were significantly higher than A₂ (10⁸ CFU/g) Treatment (p<0.05). However, other parameters e.g. RBC, HB, MCH, MCHC had no significant different. The serum lysozyme, alternative complement activity (ACH50) and IgM levels were significantly enhanced in dietary administration E. faecium(10⁸,10¹⁰CFU/g) in feeding period. Survival rate of fish by dietary administration E. faecium (10¹⁰CFU/g) was significantly higher (p<0.05) than the other groups (86.6%).