The study was conducted to determine the effect of Saccharomyces cerevisiae and Bacillus subtilis on body weight gain , some serum parameter and salmonella colonization of cecum in broiler chicks.One hundred fifty 1 day old male broiler chicks (Ross breed) were used in experiment ,the chicks were allocated into three groups and the first group as a control in randomized design(basal diet) , the second group ( basal diet with 1% saccharomyces cerevisiae and Bacillus subtilis) ,and the third group ( basal diet with 2% saccharomyces cerevisiae and Bacillus subtilis) birds in each group were fed ad libitum for a period of 38 days. The result showed that supplementation of saccharomyces cerevisiae and Bacillus subtilis 1% and 2% to the basal diet decrease cholesterol significantly ( p≤0.05) at 29 and 38 days and increase total protein p≤0.05)at 39 days , with no significant differences in another in blood parameters such as blood glucose and albumin. Body weight of treated groups significantly different( p≤0.05) at 29 and 38 days of age compared with control group. The results showed that saccharomyces cerevisiae and Bacillus subtilis decreased the number of Salmonella count of the cecal content of treated groups(38 days old) than control.