This study was the done to describe health behavior and determine affecting factors in middle aged women. The subjects of this study were 306 middle aged women, living in M city, during the period from June 28th to August. 31st 1999. The instruments for this study were Health Behavior Assesment tool developed by Kim (1998), Self esteem scale developed by Rosenberg(1965), the perceived health status scale by Lawston, et al.(1982), the Quality of life by Ro(1988), the attitude toward Climacteric symptom by Ji(1983). The data were analyzed using descriptive statistics, t-test, Pearson correlation coefficients and stepwise multiple regression. The result of this study are as follows; 1. The total mean score for Health behavior was 2.51(range 1-4). The mean scores on the subscale were 2.83 for nutrition, 2.81 for stress management, 2.71 for limitation of liking in the menstrual group, health behavior was 2.64. The mean scores on the subscale were 2.98 for nutrition, 2.85 for stress management, 2.82 for limitation of liking, 2.80 for energy conservation in the menopausal group, 2. The mean scores for cognitive-perceptual variables in the menstrual group were perception of health status: 2.61, quality of life: 3.17, self-esteem: 2.59, and attitude for climacteric symptom: 3.02. In the menopausal group the scores were perception of health status: 2.41, quality of life: 3.10, self-esteem: 2.62, attitude for climacteric symptom: 3.06. 3. Health behavior and self-esteem(r=.269, p=.000; r=.205, p=.042), attitude for climacteric symptom(r=.192, p=.005; r=.545, p=.000), quality of life(r=.385, p=.000; r= .195, p=.050) and health behavior were correlated positively, and the perception of health status and health behavior were correlated negatively(r=.-135, p=.050; r= -.207, p=.040 ) in the menstrual group and menopausal group. 4. Perception of health status, quality of life, age, self-esteem, job and marital status explained 33.7% of the variance for health behavior in the menstrual group; self-esteem and education explained 33.1% of the variance for health behavior in the menopausal group. In conclusion, health behavior should be considered when developing nursing strategies for middle-aged women, especially when dealing with perception of health status, quality of life, and self-esteem.