PURPOSE: This study purposed to supply basic data for nursing intervention plan for middleaged women healthcare and for finding solutions to nursing problems through understanding middle-aged women's depression, and to examine whether middle-aged women's depression is related with self-concept, self-efficacy, physical condition and social support. METHOD: The subjects were 200 middle-aged women aged between 35 and 60 and living in Daejon city and K city in Chungcheongnam-do, and the questionnaire survey was conducted from the 15th of August to the 18th of September in 2003 using a structured questionnaire. Collected data were analyzed through descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient and stepwise multiple regression. RESULT: Middle-aged women's depression was found to be in a negative correlation at a statistically significant level with self-concept (r=-.679, p=0.000), self-efficacy(r=-.489, p= 0.000), physical condition(r=-.650, p=0.000) and social support(r=-.526, p=0.000). The most significant variables of middle-aged women's depression was self-concept(46.2%). Combining with physical condition(13.2%) and self-efficacy(0.9%), the three variables together explained 60.3% of middle-aged women's depression. CONCLUSION: The results show that middle-aged women's depression is closely related with self-concept, self-efficacy and physical condition. Thus this study suggests that the goal of nursing intervention for middle-aged women to overcome depression should be to help them to have positive self-concept, high self-efficacy and sound physical condition.