This descriptive study was designed to identify the factors associated with weight control behaviors among 273 high school girls with normal body weight. The objectives of the study were ⅰ) to evaluate subjective obesity and satisfaction with the body shape, ⅱ) to describe the weight control behaviors and the motivation, ⅲ) to reveal the relationships between the weight control behaviors and BMI (Body Mass Index), iv) to investigate the relationships between the weight control behaviors and subjective obesity and satisfaction with the body shape, and v) to investigate the relationships between the weight control behaviors and family support. The results showed that 62.6% of the adolescent girls with normal weight perceived that they were fatty and 9.9% thought they were obese. Seventy-five percent of them were not satisfied with their body shape. Eighty percent of the participants reported the main motivation of weight control was to have an attractive appearance. In this study, self-reported weight control methods included dieting (64.8%, skipping or reducing meals), exercise (36.6%), and special dieting (20.1%) such as eating an increased amount of juice or vegetables. It was shown that the subjects who were not satisfied with their body shape and perceived themselves as fatty or obese were active in exercise, diet, and other special diets. Subjects who were on diets and special diets had a higher level of BMI than who were not on diet and special diet. Subjects who exercise had a lower level of BMI than who did not exercised. Family support was significantly related to exercise behavior. The research suggested that there is a increasing responsibility for school nurse to instruct on the body shape and weight control behaviors through health education and consultation. Also, the results suggested that it is important to develop proper diet and exercise methods for adolescents girls to maintain their weight and health.