The present study was carried out at the Poultry Research Farm, Poultry Production Dept., Faculty of Agriculture, South Valley University., Qenato investigate the effect of optizyme, phytase enzymes supplementations and their interactions on the performance of broiler chickens fed corn/soybean meal. includes 1.broiler performance, some carcass traits, some blood constituents and nitrogen retention efficiency%. The experimental design was 3×2 factorial design, three Optizyme enzyme levels (0, 250 and 500 µg/kg) and two Phytase enzyme levels (0 and 1500 FTU/kg). The results showed that the level of 250 or 500 mg optizyme and 1500 FTU phytase improved  body weight gain (BWG) at end of the experiment,  feed consumption (FC) from one day old to three wks of age, numerically dressed percentage, elevating blood plasma alkaline phosphatase, triglycerides, calcium and enhanced nitrogen retention efficiency. The results concluded that the optizyme level (250 or 500 mg) and 1500 FTU phytase enhanced the performance of IR broiler chickens in the criteria studied.