This study conducted to investigate the effects of feeding Fermkito 50 on the egg production and egg quality hens. One hundred forty four, 50 weeks old ISA brown commercial layer, were used in a 28 d growth assay. Dietary treatments included 1) control(basal diet), 2) FERMO.5(based diet+0.5% Fermkito), 2) FERM1.0(basal diet+1.0% Fermkito), 3) FERM+YU(basal diet+0.5% Fermkito and 0.05% yucca extract). Overall (d 0 to 28), egg production tended to increase as the concentration of Fermkito 50 in the diets was increased without significant difference(P〈0.05). As adding level of Fermkito 50 increased in the diets, egg weight tended to increase. Laying hens fed FERM+YU diet were higher egg weight than laying hens fed control diet(P〈0.05). Egg shell breaking strength was not influenced by Fermkito 50. As adding level of Fermkito 50 was increased in the diets, yolk color tended to increase. Laying hens fed FERM+YU diet had improved egg yolk index compared to laying hens fed control diet. Total-cholesterol of egg yolk in FERM1.0 and FERM+YU treatments was significantly decreased compared to that in control diet(p〈0.05). Total-cholesterol and triglyceride concentrations in serum tended to increase as the concentration of Fermkito 50 in the diets was decreased(P〈0.05). Also, HDL-cholesterol concentration in serum with FERM1.0 and FEUM+YU treatments was significantly higher than control diet(P〈0.05). However, LDL-cholesterol concentration in serum with FERM1.0 and FERM0.5+YU treatments was significantly lower than control diet(P〈0.05). In conclusion, supplemental Fermkito 50 in laying hen diets can be used to improve egg quality.