For the purpose of searching for the factors for improvement in cutaneous lesions of atopic dermatitis, we evaluated two factors, namely, change in the housing environment and withdrawal of corticosteroid in a group of patients whose clinical course had been observed for more than one year. The condition of illness was judged by a combination of VAS scoring of cutaneous lesions, laboratory data (IgE, LDH, eosinophil) and evaluation by the patient himself. The results showed a significant difference (p = 0.143) by Fisher's direct probability for the tendency to improve in the group in which the housing environment had changed and p = 0.266 for the tendency to improve in the group in which corticosteroid was withdrawn. When the tendency to improve by either change in the housing environment or corticosteroid withdrawal was examined, the p value was 0.028 at 5% level of significance. That is, the findings in this study suggest that atopic dermatitis will improve in the presence of either or both of these two factors at 5% level of significance. Factors regulating the condition of illness in atopic dermatitis are diverse. Analysis using only one of these factors cannot easily show a statistically significant difference. So studies involving two or more factors are needed.