The purpose of this study was to investigate the relationships between demographic and psychological variables and clothing behavior with reference to sex difference in adult and elderly groups. The clothing behavior was measured by Clothing importance, Interest, Conformity, Modesty, Psychological dependence, Aesthetics, Management, Fashion, and Clothing satis-faction. Psychological variables in this study were self-esteem and life-satisfaction, and demographic variables were sex, education, family type, health, and clothing expenditure. The hypotheses set up in this study were as follows : First, a causal relationship will exist between demographic and psychological variables and clothing behavior in both adult and elderly groups. Second, in clothing behavior a main effect will exist between male and female groups and between adult and elderly groups. Third, in clothing behavior and interaction effect will exist between sex and age. The subjects of this study were 496 adult males, 459 elderly males, and 446 elderly females residing in Pusan area. The material used in this study to measure the clothing behavior was a 5-point rating scale with 31 items in 9 sub-areas developed by the author. The data were collected by five investigatiors well trained in interview before-hand. The following conclusions were obtained from the relults and discussions of this study : First, sex, education, and clothing expendi-ture has a causal relationship with clothing behavior in adult group. Females, higher-educated group, and the group with more clothing expenditure reveal higher concern for clothing. In adult group life-satisfaction does not have any causal relationship with clothing behavior in general execpt for clothing satis-to Psychological dependence, Aesthetics, Management, and Clothing satisfaction in the group. Second, in elderly group sex, education, and health significantly contribute to clothing behavior. A cencern for clothing is higher in female, higher-educated group, and the group with higher perception in health. Self-esteem has a causal relationship with Clothing importance, Conformity, Management, and Clothing satisfaction, whereas life-satisfaction has a strong causal relationship with clothing behavior in general. Third, in both adult and elderly groups a sig-nificant sex diference exists in clothing behavior. Females show higher concern for Clothing importance, Interest, Psychological dependence, Aesthetics, Management, and Fashion than males. On the other hand, males reveal higher concern for Conformity and Clothing satisfaction than females. Fourth, a significant interaction effect exists between age and sex, while elderly females show lower concern for Clothing importance, Interest, and Psychological dependence than adult females, elderly males show higher concern for the same sub-areas of clothing behavior than adult males. This signifies the increase of the concern for clothing in elderly males with the decrease of social activities. Fifth, adult female group reveals lower Con-formity in clothing compared with the other groups, which signifies the higher individuality in clothing behavior. On the other hand, the elderly groups show significantly higher Conformity than the adult groups. this signifies the importance of the consideration for the variables other than individuality in clothing behavior for the group.