Korean herb medicine, Panax ginseng, has been observed to have strong anti-inflammatory component in the chloroform extracts and in the single component of ginseng. It has also been reported that 20(s) G-Rg3 suppressed strongly histamine release from mast cells due to stimulation with compound 48/80 and substance P. We reported that ginseng saponine such as total saponin, protopanaxadiol, and protopanaxatriol inhibited in part of the mediator release in antigen-induced airway smooth muscle contractions. We also reported that single components such as Rg1, Rg2, and Rc inhibited the releases of histamine and leukotrienes during the activation of guinea pig lung mast cells. These results supported that single component of ginsenosides decreased histamine release by the inhibition of PLD activity during mast cell actiyation. Allergic reactions and asthmatic disorders are caused by the mediator release during the activation of mast cells and basophils by cross-linkage of plasma membrane-bound IgGl or IgE, and subsequent bridging of IgGl- or IgE-Fc receptors. When mast cell membrane receptors are activated by cross-linkage with antigen-antibody, the enzyme system in the cell membrane are activated. These enzymes such as tyrosine kinase, PLC, PLD, phospholipase A2, adenylate cyclase, MT etc are activated. This process is intimately related to the activation of a variety of phospholipid metabolic pathway and the generation of a number of second messengers. The results lead to exocytosis of preformed inflammatory mediators and synthesis of newly formed mediators.