Introduction:The immune system is the strongest mechanism of the body to defend itself against all kinds of foreign agents.However,a malfunctioning immune system can play a devastating role by causing many diseases and disorders in the body.Diseases and disorders of the immune system are classified depending on the activity of the immune system.An overactive immune system has the potential to compromise health just as much as an underactive immune system.The use of natural compounds will be effective in modulating immune system disorders.One of the terms that is mentioned in Persian medicine as a fortifying factor for body,is “padzahr”.In this study,boiled water of padzahr was used to investigate the mentioned effects.Method:The studied population included 14 male Balb/c mice that were randomly divided into two equal groups and immunized with SRBC antigen.Mice in the treatment group received padzahr water(200 microliters)daily for two weeks from the beginning of the study.Humoral immunity and cellular immunity,respiratory burst ability,nitric oxide production rate and spleen cell proliferation index were measured.Result:The obtained results indicate a significant increase in the anti-SRBC antibody titer in the serum of mice in the treatment group at the same time as a decrease in the intensity of the cellular reaction compared to the control group.The proliferation rate of spleen cells was significantly increased compared to the control group.Conclusion:Since the intensity of respiratory explosion and the ability to produce nitric oxide in phagocytic cells are significantly reduced,it seems that padzahr water can be considered as a natural compound that modulates the immune system.