The Immune System is the most complex biological systems in the body. At the time of infection immune system go under the attack of a large number of viruses, bacteria and fungi. The immune system is a part of body to detect the pathogen by using a specific receptor to produce immediately response by the activation of immune components cells, cytokines, chemokines and also release of inflammatory mediator. They modulate and potentiate the immune system. Medicinal plants impart significant roles in the prevention of human being from various pathogenic microorganisms and the diseases. In nature there are various medicinal plants which are used as immunomodulator agents. This review is an attempt to put various plants in one place which are used as immunomodulatory agents.