The validity of the space characteristic theory and the measurement method were investigated experimentally. For this purpose, we have proposed two new experimental methods. An experiment was carried out using one of them. It was confirmed that the distribution of θ is calculable from experimental data by the measurement method, and θ of subject was fairly stable during the experiment. From these results, it was concluded that the validity of the theory and the measurement method were verified, and that the research based on the theory is practicable and effective for the study of internal process of subjects in a game situation. The research based on this theory is very different in its experimental method, the way to analyze data, and the interpretation of data, from traditional one. We consider that the research based on the space characteristic theory will indicate a new direction for the study of choice behavior in game situations, and contribute to the understanding of the motivational, and cognitive aspect of choice process which Doi and Imai (1986) have discussed