Characteristics of 181 patients with steroid-dependent intractable asthma (SDIA) who were admitted to our hospital and had spa therapy for last 10 years were examined in relation to the methods of spa therapy. For last 10 years, three kinds ofspa therapies were administered: spa therapy A (swimming training in a hot spring pool) in the first atage (1982-1985), spa therapy B (swimming training + inhalation of iodine salt solution) in the middle stage (1986 -1989), and spa therapy C (swimming training + inhalation of iodine salt solution + fango therapy) in the last stage (1990-1991) of this study. 1. The number of patients with SDIA who were admitted to our hospital and had spa therapy tended to increase from 2 in 1986 to 35 in 1991. 2. The number of SDIA patients over the age of 60 or over the age at onset of 40 tended to increase from the first stage to the last stage. 3. The proportion of patients from distant areas (prefectures other than Tottori) was decreasing for the last stage, although the number of these patients was increasing in recent years. 4. The proportions of patients divided by serum IgE levels and by clinical asthma types did not change for last 10 years. 5. The proportion of type Ib and type II asthma was considerably high in patients with SDIA for last 10 years. 6. Clinical effects of spa therapy were observed in 21 of the 30 (70.0%)patients with SDIA in the first stage (1982-1985) with spa therapy A, 68 of the 83 (74.7%) patients with SDIA in the middle stage (1986-1989) with spa therapy B, and 61 of the 68 (89.7%) patients with SDIA in the last stage (1990-1991) with spa therapy C.