The aim of this study is to analyse the patterns of interpersonal perception from the viewpoint of personality. A pattern of interpersonal perception is regarded as a subordinate socio-psychological concept like attitude, opinion and belief. Personality is here deemed as the general behavior-modality which appears in the interpersonal situation and it is reflected on the patterns of perception. The writer also tried to use empathy, a fundamental concept in the previous studies, as an independent variable of the perception-patterns. In the present report, Part I, the composition of the scale and the methods of measuring behavior modality and empathy are to be described. 1. Composition of Semantic Differential Test: It is a fundamental problem in the analysis of perception pattern how to describe and classify the relation between oneself and others in the interpersonal situation. In the present study, a new Semantic Differential Test for the group activities and membership was composed, the technique by Osgood et al. being referred to. By means of ten concepts regarding a group, samples of adjectives were collected and scales were arranged on the basis of 25 pairs of opposite adjectives. A group of 54 subjects, second-year high school students, was required to rate eight concepts regarding the group in terms of the above scales. On the basis of these data correlations were obtained between the scales, and in terms of thefactor-analysis three factors, Friendliness-Evaluation,Dominance-Potency,Participation-Activity, were sampled out. The Semantic Differential Test, consisting of a couple scales for each factors was thus composed. 2. Measurement on the Behavior Modality: The general behavior modality indicated in the interpersonal situation was measured by the mutual ratings among the classmates. Eight types of the hypothetical modality were set up by the combinations of three Semantic Differential factors which formed the patterns of the perception of oneself and others. On this basis the data of the mutual ratings were classified and the modality types were thus judged. Exp. 1) In order to examine these hypothetical types of modality, a modality-measurement was conducted for the subjects, a total of 180 second-year high school. The results indicated that these actually existed only six among the eight types of the hypothetical modality. Exp. 2) In order to clarify the psychological significance of the hypothetical modality, afact-or-analysis was attempted between the actual modality types, 54 third-year high school students serving as subjects. It was evident from the result that three statistically independent were not independent of each other in psychological meaning, and it was consequently verified that there did not exist eight types of the hypothetical modality in practice. 3. Measurement of Empathy: There are two standpoints employed in the method of empathy measurement, that is, phenomenological and depth-psychological. The potential, depthpsychological empathy was here measured, according to the latter standpoint. It was required to rate in terms of the Semantic Differential Scale these sentences which described an outlook of a human being independent of the actual interpersonal relations. The degree of empathy was measured by the deviation of each datum from the averaged norm of all members. Exp. 1) In order to investigate whether the appropriate sensibility would be measured for the cue, we examine the relation of the empathy to the patterns of perception, a total 180 second-year high school students serving as subjects. The result indicated that what was measured was not the appropriate sensibility but only the sensitivity for the cue. Exp. 2) In the above investigation, we tried to measure the empathy from the deviation of perception the concept and sentence-rating, 260 subjects of second-year high school students.