The thermal environment in summer at a large rooftop garden on a commercial building was investigated. Results are summarized as follows. 1. Resting places in a tree shade had non-"Hot" condition when solar radiation was large, while wind speed was around 1m/s in there and consequently SET* was higher than that in shaded open spaces. 2. The rooftop garden had well-shaded foot paths that supplied non-"Hot" condition during most of the afternoon. 3. A tree shade was desirable on a fine day, while open spaces were desirable on a cloudy day. 4. SET* was most appropriate index to evaluate the relationship between human behaviors and thermal environment.
