A total of 600 fertile broiler breeder eggs were divided randomly into 6 treatments with four replicates. On the 7th day of incubation, 0.1 ml solution was in ovo injected into the air cell. The first group served as control without any injection ,while the 2nd group was injected with 0.1ml saline solution, the 3th group was injected with 0.1 ml nano organic iron, the 4th group was injected with 0.1 ml nano inorganic iron, the 5th group was injected with 0.1 ml inorganic iron and the 6th group was injected with 0.1 ml organic iron .The injected dose of each iron solution is 0.1ml/egg containing 75 ppb of different iron sources (nano, inorganic and organic). After incubation, chicks were reared up to 6wks of age and productive performance and immune response parameters were measured. Results indicated that, supplemental iron have increased the levels of immunoglobulins( IgG and IgM) and relative weights of spleen, bursa and thymus, and stimulated some histological change in the immune related organs which may result in improvement of chick immunity .