Recently, the research and development of the system which is able to obtain the relaxation effect has been actively performed. Most of the moderns have some stresses and require the request for healing, and the early development of the relaxation system is expected. For example, the system which sounds and images are presented to the user, the relaxation effect is judged from the vital signals of heart beat, pulse rate and so on, and the contents of presentation is tuned to raise its effect has been developed. In this research, we aim to construct the system to adjust the automatic operation to obtain the relaxation effect by presenting the sound to the user, and judging the degree of relaxation based on the brain wave information. In this paper, as an advance research on the construction of this system, we try to analyze the features of the brain wave measured in a different state and to find the index that judges the relaxation degree.