We studied the 1-type isoproterenol inhalation therapy for patients with severe asthmatic attacks who were admitted at the Department of Allergy of National Children's Hospital from 1981 to 1991. One hour after l-type isoproterenol inhalation therapy, statistically significant effects were noted with regard to the asthmatic status. Moreover, no side effect was found amoung the subjects. From these data, 1-type isoproterenol inhalation therapy is thought to be effective for severe asthmatic attacks.