This study aims to examine the ability ofthreonine (TH), citric acid (CA), sodium sulphate (SS) or their mixture to improve the utilization of broiler low protein diets. A total number of 240 Cobb broilers 10 day old were randomly distributed into eight groups received control diet containing Cobb nutritional requirements,  diet containing 2 percentage lower crude protein than control diet without the adequate requirement of threonine compare to threonine cobb requirement(LTH), diet contain 2 percentage lower crude protein than control diet with synthetic threonine equal to control group and cobb requirement(LP), LP +0.3 % citric acid (CA), LP +0.3% Anhydrous sodium sulphate (SS) , LP+0.3% CA + 0.3 % SS, LP+ 0.05% threonine  (TH) and LP +0.05% TH + 0.3% CA + 0.3 % SS. The result obtained showed that, at 21 day, using LP diet significantly decreased broiler body weight compared to control diet while all feed additives improved weight gain and feed conversion compared to LP. The birds fed mixture of TH+CA+SS recorded the highest value of body weight and the best feed conversion. At 35 day, the birds fed mixture of TH+CA+SS recorded significantly higher body weight value and lower feed conversion by 5.62, 7.83 %, respectively, compared to those fed control diet while the carcass values recorded by different treatments did not differ significantly. Compared to other treatments, birds fed mixture of TH+CA+SS recorded the highest values of total protein, albumin and total cholesterol in blood analysis. We can conclude that addition of TH, CA or SS to LP diet improved the broiler performance as well as those fed control diet while addition of mixture of TH+CA+SS surpassed the control diet performance and recorded the highest value of economic efficiency .