Due to prices fluctuations of inputs, outputs and global warming as a challenge facing poultry sector, in broiler flocks, there are several strains available to breeders' addition to sex difference.Strains and ganders differ slightly in immune-response and subsequently in productive performance. Our study investigates the cellular mediated immunity using PHA-P, some blood profiles and expression of immunity related genes (CD1b/1 & IL4I1/1) in two broiler strains. Number of six hundred chicks of Ross-308 and Cobb-500 strains was distributed as random in a completely randomized design (CRD) to 4 groups (Ross males, Ross females, Cobb males and Cobb females). At 35 day of age, blood samples werecollected randomly for gene expression and blood analysis.Our results concluded that Cobb males had the best FCR when compared to other groups.  The greatest relative growth rate was obtained from Cobb males. The average of EBI, RPI and EPEF values for Ross males recorded the highest values than all other groups. At the study of immune response, the Cobb strain had significantly hyper responder to PHA-P injection compared to Ross.The blood globulin level of Cobb males had the highestvalue than other groups. Due to lipid profile; Cobb males and Ross females have the lower values of total cholesterol and Ross strain had highly significant value of total lipids. The Cobb strain had a higher total protein than Ross. The Cobb strain had higher blood Phosphorus level than Ross. At the study of molecular genetic analysis, CD1b/1 expression was higher for Ross males and Ross females than other groups andIL4I1/1 expression was higher in Ross males and Cobb females than other groups. At the end of experiment, results suggest that Ross males had more immune competence than other studied three groupsand males of both strains proved efficient to growth performance than females.