PURPOSE: The purpose of this study was to investigate the relationship between health locus of control(HLOC) and eating behavior in obese middle school girls. METHOD: The sample consisted of 170 obese middle school girls in Seoul. RESULT: 1. The average scores of HLOC were HLOC-Internal ; 4.11, HLOC-External ; 2.45, HLOC-Chance ; 2.09. 2. The average scores of eating behavior factors were Disinhibition ; 2.69, Dietary Restraint ; 2.67, Hunger ; 2.55. 3.The HLOC-Internal and eating behavior(dietary restraint and hunger) were correlated positively. The HLOC-Chance and disinhibition was correlated positively. But HLOC-Chance and dietary restraint was correlated negatively. The HLOC-External and eating behavior(dietary restraint, disinhibition and hunger) were correlated positively. 4. There was not a significant difference in HLOC depending on the demographic characteristics(grade, degree of obesity, father & mother's body shape, existence of obese sibling). There were significant differences in HLOC-Internal and HLOC-External according to thinking about oneself who is obese or not. 5. There was not a significant difference in eating behavior depending on the demographic characteristics(grade, degree of obesity, father & mother's body shape, existence of obese sibling, perception of oneself as a obese). CONCLUSION: This study has shown a correlation between HLOC and eating behavior. As a result of these findings, clinical and school nurses should be involved in management and counselling of obese girls concerning individual health locus of control and eating behavior.