In this study, it is supposed that the human recognition system for odor intensity can be classified into systems of physiological intensity and sensory intensity. The former is the intensity based on the physiological response to olfaction, the latter is the intensity dependent on psychological properties such as odor qualities and odor hedonics. The purpose of this study is to make clear the relationship between physiological intensity and sensory intensity. In this paper, therefore, the quantitative relationships between all physiological intensities of odorous compounds were evaluated in experimental subjects by means of the sensory similarity test, and the impacts of the odor hedonics on the sensory intensity were examined based on the correlations between the measured sensory intensities and the hedonics of all subjects. As a result, it was confirmed that a linear relation was established between the psychological impacting factor alpha, which was the ratio of the sensory intensity to the physiological intensity, and odor hedonics. It was also estimated that methylamine had a maximum physiological intensity and ethyl isobutyrate a minimum one based on the equivalent sensory intensity.