Corynebacterium was used as an immune stimulant to evaluate the immune response of chickens against fowl pox virus and fowl pox vaccine. The immune response of chicken was judged by measurement of cell mediated immunity which included Lymphocyte transformation activity, by using glucose consumption assay, macrophage activity percentage and index against Candida albicans cells. On the other hand, the humoral immunity was evaluated by determination of total serum portein, passive haemoagglutination (PHA) and neutralizing antibodies. The effect of C. cutis extract on the resistance of chicken against the challenge with virulent fowl pox virus gave positive and negative action, these included protection (8%) and gave significant increase in ‘both cell mediated and humoral immunity in comparison with control chicks. Birds treatd with C. cutis extracts 3 days before vaccination against fowl pox virus, gave significant increase in lymphocyte transformation, macrophage activity, total serum protein, PHA and neutralizing antibodies. The protection percentage of vaccinated and treated groups agaisnt challenge with virulent fowl pox was 100 % as compared with 88% in vaccinatd birds without treatment with C. cutis.