Using the rabbit ear steel chamber technique devised by Williams and modified by Ohsaki, biopharmacological reaction of topically applied cortico-steroid hormone was investigated. Solutions of cortico-steroid hormone (beta-methasone) kept under three thermal conditions, e.g., 37℃, 20℃, and 4℃, respectively, were poured into steel chambers with a microsyringe, and the changes of microcirculation of the vascularization in the chamber were observed chronologically. Changes of microcirculation were stasis, hemorrhage, sludge, and exsudate; and were set as the criteria of grade of inflammatory process. The results obtained were as follows: 1. Strong anti-inflammatory effects was showed by administration of beta-methasone at 37℃. 2. Beta-methasone at 20℃ showed less anti-inflammatory action than those at 37℃. 3. Application of beta-methasone at 4℃ acted as a vigorous inflammatory agent. This phenomenon may be attributed to the stimulating effect of cold solutions. Consequently, it seemed that topical application of beta-methasone was most effective when used at 37℃.