In this study, the relationships among obesity, food behavior, and personality traits were studied in male and female elementary school children. The obesity rates were calculated via the measured heights and weights of the subjects. Food behavior was surveyed via a questionnaire. Personality traits were evaluated using an authorized personality test. The obesity rates in the child subjects in this study were 34.1%in the male children, and 28.7% in the female children, and the rates of underweight were 18.2% in the males and 28.7% in the females. The percentage of obese children was slightly higher in the male population than in the female population. With regard to food behavior, the females evidenced significantly higher points than the males, particularly on the items designated 'slow eating' and 'stop eating upon satiety'. Among the personality traits assessed herein, which included emotional stability, general activity, sociability, masculinity, responsibility, reflectiveness, and superiority, the females evidenced significantly higher sociability scores than the males. The personality traits did not appear to be significantly associated with the obesity rate. However, the obese children scored lowest on all personality traits among the three groups. In terms of the relationship between food behavior and personality traits, children with high stability, sociability, responsibility, and superiority also had significantly higher food behavior scores. These results imply that the maintenance of good food behavior may enhance stability, sociability, responsibility, and superiority in children.