Serum cortisol levels before and after spa therapy were compared in 30 patients with steroid-dependent intractable asthma (SDIA) in relation to clinical asthma types. 1. The mean level of serum cortisol in patients with type la-1 asthma was 2.0±0.7mcg/dℓ before spa therapy, and significantly increased to 9.0±3.1mcg/dℓ　(p<0.001). The serum cortisol level of patients with type la-2 also significantly increased from 3.3±1.5mcg/dℓ before spa therapy to 5.9±3.1 mcg/dℓ after the therapy (p<0.05). 2. The level of serum cortisol in patients with type Ib increased from 4.0±1.6mcg/dℓ to 7.8±1.4mcg/ dℓ after spa therapy (p<0.001). In contrast, the serum cortisol levels in patients with type II were not significantly different before (2.7±1.3mcg/dℓ) and after spa therapy (3.5±3.0mcg/dℓ). The results showed that an increase in the levels of serum cortisol by spa therapy was more clearly observed in patients with type la-1 asthma compared to that in type la-2 or type Ib, and that, in contrast, the serum cortisol levels in patients with type II asthma did not significantly increase by spa therapy, since their asthma attacks were always severe and chronic in spite of long-term glucocorticoid regimen.