Purpose: The purpose of the study is to identify structural relationship among exercise imagery, physical activity, and health-related quality of life of adults. Methods: Five hundred questionnaires were initially distributed to college students, company employees and sports center members(male: 273, female: 194, Mage=39.21). Among them, total 467 were finally used in this study. Exercise imagery scale, weekly leisure-time exercise questionnaire and short-form health survey-36 were revised into Korean and applied in the study. Frequency analysis, correlation analysis, and structural equation modeling were carried out to test the possible relationship among exercise imagery, physical activity, and health-related quality of life. All analyses were conducted by SPSS 18.0 and AMOS 18. Results: Results indicated that there were positive relationship among exercise imagery, physical activity, and health-related quality of life of adults. In specific, exercise imagery and physical activity had significant positive relationship with vitality which was sub-factor of psychological health-related quality of life. Additionally, exercise imagery was significant factor to physical health-related quality and physical activity. The finding ultimately revealed that a hypothesized research model showed the significant model fit after modification. But it was showed the difference with sex. Conclusion: This study suggests that cognitive intervention strategies aimed at exercise imagery could be significant to promote physical activity and its related health-related quality of life. As it was existed the difference with sex, there will be necessary another studies which is concerned about various variables.