To evaluate the antiatopic effect of Korea Red Ginseng (RG, steamed root of Panax ginseng C.A. Meyer, Family Araliaceae), its inhibitory effect on passive cutaneous anaphylaxis reaction and itching in mice was measured. RG and its ingredient saponin fraction (SF) potently inhibited passive cutaneous anaphylaxis (PCA) reaction and scratching behaviors. RG at a dose of 100 mg/kg and SF at a dose of 50 mg/kg significantly inhibited the scratching frequency by 32% and 38%, respectively. RG and SF also inhibited the degranulation and protein expression of tumor necrosis factor $(TNF)-{alpha}$ and interleukin (IL)-4 of RBL-2H3 cells induced by IgE-antign complex. However, polysaccharide fraction of RG did not inhibit it. Based on these findings, RG can improve allergic skin disorders atopic dermatitis and contact dermatitis by the regulation of $TNF-{alpha}$, and IL-4 produced by mast cells and basophils and their membrane stabilization.