The present invention relates to a pharmaceutical composition and health supplement for preventing or treating atopic dermatitis, the composition and supplement having as active ingredients extract of a galenical mixture including sophora root, licorice, lonicer aflower, Korean angelica root, Korean aralia root, saussurea root, seselos radix, zizyphus spinosi, Houttuynia cordata, forsythia fruit, lappa fruit, Epimedium koreanum Nakai, ginseng, lithospermum, oleoresin, cnidium, scorophulariae radix, and reynoutria, or lactobacillus fermentation of the galenical extract prepared by inoculating lactobacillus to the galenical extract and fermenting same. The galenical extract or the galenical extract fermentation of the present invention achieves reduced scratching, decreases clinical features of atopic symptoms such as erythema, itchiness and dry skin, edema and hematoma, erosion, and lichenification, and reduces IgE concentration in blood, which is related to exogenous atopic dermatitis, in laboratory animal models of atopic dermatitis, and is thereby, useful for preventing or treating atopic dermatitis.