Objectives: The purpose of this study was to examine health locus of control (HLC) related obesity and the eating behaviors in Korean adults. Methods: The online survey was conducted on 1500 adults and middle aged over the age of 19 years of age (www.embrain.com). The data collected were analyzed by descriptive statistics, the t-test, ANOVA and Scheffè test. Results: The average scores of HLC related obesity (5 points) were internal HLC 3.95(±0.51), powerful others HLC 2.89(±0.66), and Chance HLC 2.63(±0.69). The average scores of eating behavior factors (5 points) were dietary restraint 2.67(±0.66), disinhibition 3.20(±0.64), hunger 2.81(±0.69). The subject’s characteristics with ‘Obese parent’, ‘perception of oneself as a obese’, and ‘higher BMI’ were higher internal HLC, the subject’s characteristics with ‘perception of oneself as a obese’, ‘having an control diet experience’, and, ‘higher BMI’ were higher dietary restraint. Conclusions: The findings of this study suggest that management of adult obesity need individual management according to characteristics of ‘HLC’ and ‘eating behavior factors’ for effective nursing intervention.