This study was performed to investigate the effectiveness of nutrition education and exercise intervention in a weight management program. The subjects were 24 obese women whose body mass index (BMI) was over $25kg/m^2$. Nutrition education was given once a week, and subjects did swimming three times a week. The program lasted for 12 weeks. Nutrient intakes were assessed by 24 hour recall method. Also food habits, dietary behavior and nutrition knowledge were examined by self-administered questionnaires before and after the weight control program. Height, weight, body composition and blood composition were measured before and after the weight control program. Over the 12 weeks in the weight control program, body weight significantly decreased from 69.7kg to 65.8kg(p<0.001). Body fat and BMI also significantly decreased(p<0.001). Cholesterol level significantly decreased at p<0.001 and blood sugar also significantly decreased (p<0.05). After taking nutrition education, dietary behavior and nutritional knowledge scores increased, energy intakes decreased from 1426.5kcal to 1408.5kcal and calcium from animal products significantly increased(p<0.05). A negative correlation between nutrition knowledge and BMI(r=-0.42) existed(p<0.05). A negative correlation of eating behavior with EER(r=-0.48) showed(p<0.05). We concluded that combined nutrition education and exercise was an optimal method for reducing weight.