The purpose of this study is to look into the relationship among self-discrepancy, discrepancy reduction expectancy, emotion and physical symptoms based on the self-discrepancy theory. In order to achieve the objective of this study, surveys using selves questionnaire, emotion questionnaire and physical symptoms questionnaire were administered to a total number of 247 university students. The data collected from the surveys were statistically analysed. The major findings of this study are as presented below: (1) The correlation between actual: ideal discrepancy and depression, and the correlation between actual: ought discrepancy and anxiety were significant, respectively. These results have led to the support of the basic hypothesis of self-discrepancy theory. (2) In the correlation analysis between self-discrepancy and anger, the correlation between actual: ideal discrepancy and anger was not significant. However, the correlation between actual: ought discrepancy and trait anger was significant. (3) The correlation between discrepancy reduction expectancy and positive emotion was significant. (4) In the analysis of the relationship between self-discrepancy and physical health, the correlation between actual: ideal discrepancy and headaches, and the correlation between actual: ideal discrepancy and digestive symptoms, have both been found to be significant. The correlation between actual ought discrepancy and digestive symptoms were also significant. (5) Regression analyses revealed that digestive symptom was affected by actual: ought discrepancy, 4 physical symptoms (headaches, digestive symptoms, insomnia, and heart symptoms) were affected by anxiety, and insomnia and heart symptoms were affected by state-anger. Finally, the limitations of the present study and implications for future studies are discussed.