To evaluate the effects of β glucan on innate and adaptive immune responses of broilers chickens vaccinated for routine vaccination with Newcastle disease virus (NDV) and Avian Influenza H9N2 (AIV) vaccines. A total of 180 chicks of one-day old Hubbard local breedThey were divided into three groups (sixty chicks for each group). The first group fed with normal broiler diet without any additives and served as control group, while the other two groups consumed diets contained (200mg , 400mg pure β glucan /kg diet respectively for twenty four days of the experimental period. We noticed that, the administration of β glucan to broiler chickens early in life increased significantly (p<0.05) the nitric oxide levels, lysozyme activity, phagocytic activity, and phagocytic index , in addition improved the oxidative state by decreasing malondialdehyde (MDA) and increasing glutathione (GSH) and. High concentration of β glucan improves immune response to NDV and AIV vaccines.