This study was carried out with 505(243 boys and 262 girls in the Sungnam area) high school students to investigate the effects of eating behavior and anthropometric variables of weight and height on excercise performance. General characteristics about subjects and eating behavior were surveyed by questionnaire, anthropometric data were collected using two methods. The weight and height of subjects in 1996 were measured, but the same data in 1995 were collected from health records of each student. Body fat content of subjects was measured by BIA(Body Impedance Analysis). The grades of exercise performance, which were evaluated by physical education teachers were collected from records of a physical strength test score of each subject. From these, the following result were found. Groups with different eating behaviors such as skipping meals, overeating, food preference for a specific food(milk, carbonated drink etc.) were significantly different in their weight and height and body fat contents. The growth rate of height in first and second grade boys was significantly higher than that for grade boys. The amount of weight gain from second grade to third grade was significantly more than that of other grades both for boys and girls. The mean of BMI was $21.66pm{2.95}$ in boy, $21.50pm{2.62}$ in girls. The percentage of body fat was $24.91pm{6.55%}$ in boy $34.73pm{4.88%}$ in girls. Amounts of body fat were significantly increased in third grade. The group with higher fat content and the higher BMI group had lower values of physical strength. And the ability to exercises perform decreased significantly by promotion of grade. The other variables such as degree of concern about weight control and preference of exercise, and frequencies of exercise per week were significant factors in body fat content and physical strength. As a countermeasure for these problems, nutrition and health education must be developed for adolescents and a practical, proper physical activity guidance campaign for them is necessary.