Provided is an herbal composition including an extract from a combination of herbs including at least five of Forsythia suspensa, Scutellaria baicalensis, Bupleurum chinese, Magnolia officinalis, Agastache rugosa, Astragalus membranaceus, Atractylodes macrocephala, and seeds of Ligustrum lucidum. Also provided is a method for preparing the herbal composition and a method for preventing or treating a viral infection by administering an effective amount of the herbal composition to a subject in need thereof.