The Tama river park has various natural environments, and there are a lot of visitors. Visitors enjoy the spectacle, the murmuring sound, and hydrophile, etc. , and are strolling with calm feelings. These feelings are defined as the healing effect. This biological reaction can be considered to be a state that the stress is eased. Therefore, the healing effect of the river front can do the quantitative evaluation by the stress index of the biological reaction.

In this study, the quantitative evaluation in the healing effect was done by using the amylase revitalization value of the saliva inside as a stress index. Four items were taken up as a river environments, and the degree of the contribution of four factors to the healing effect was structured by field investigation. By using these results, the evaluation technique of water environment can be developed using stress index.