Acute urticaria usually appears as sthenia-heat syndrome, but quite a few of them are shown as asthenia-cold syndromes. Under the guidance of the theory of exterier syndrome of Shaoyin and the principle of warming yang to relieve exterior syndrome,the disease was treated with the prescriptions of modified Mahuang Fuzi Xixin Docoction, Mahuang Fuzi Gancao Docoction and so on. The experience is introduced on the diagnosis and treatment of acute urticaria from exterior syndrome of Shaoyin. And two proven cases are presented.