The effect of feeding different levels of sodium bentonite on Japanese quail chicks performance was studied. An experiment of 42 days was conducted with a flock of 240 unsexed one- day old chicks, distributed at random into 4 groups each in 3 replicates. Treatments were control no additive, T1containing 2% sodium bentonite, T2 containing 4% sodium bentonit and T3 containing 6% sodium bentonit). All chicks had free access to feed and water ad libitum during the 6-wk experiment. Average daily gain, feed intake and feed conversion efficiency were determined. The results indicated that, chicks fed 4% and 6 % bentonite had higher body weight gain at 42 days; performance index lower feed intake; and better feed conversion ratio compared to the control diet. Feeding diet containing 6% had the highest total serum protein, globulin, Glucose and AST concentrations; moreover lower in LDL and HDL than the control diet. No significant effect of different levels of sodium bentonite on the averages values of carcass characteristics. Evidently, it is concluded that the dietary supplementation of Japanese quail chicks with 6% sodium bentonit resulted in considerable improvement in the growth and economic efficiency without adverse effects on carcass characteristics and constituents of blood serum.