This study aims to develop a practical methodology within the parameter of experimental psychology t o obtain broader information between the interaction of humans and building environment during fire condition, and thus to find out the causes of psychological stress or physiopsychological injury in fire. In part I of the study we developed a visual experience simulator on the assumption that visual perception dominates psychological interactions between humans and building environment. Through a series of experiments with this simulator, it became possible to put the complete response of an individual under observation. Data showed the causes that led to the occupant’s confusion of recognizing direction or standing point. This proposal should be helpful in evaluating the safety of building elements in light of the ease of perception on the part of the occupants. Part II, the aim of the study was to investigate the physiopsychological impact from the presence of CO gas. By applying the theoretical model of experimental psychology, the existence of physiopsychological impact in case of acute CO poisoning was identified. The experimental method proposed here and its results should be helpful in improving contemporary t e s t methods. The methods estimate gas toxicity through comparison analysis based on the immobilization of CO gas poisoned animals.