The purpose of this study was to investigate relationships among high school students` internet addiction, negative emotions, metacogniton and meta-mood, and to examine how the negative emotions, metacogniton and meta-mood influence internet addiction. This study proposed the path model which negative emotions led to internet addiction through the mediation of metacogniton and meta-mood. Additionally, this study examined if this path model could apply to both high school boys and girls. For this study, a sample of 424 high school students in Seou1(296 boys, 137 girls) completed the questionnaires: Internet Addiction Scale, Metacognitions Questionnaire-30, Trait Meta-Mood Scale, Beck Depression Inventory and Beck Anxiety Inventory. The data were analyzed by SPSS 12.0 and AMOS 7.0 program. The results were as follows. First, the analyses revealed that assumed path model was applicable to high school boys. In high school boys, negative emotions had significant effect on internet addiction through the mediation of metacogniton but no significant direct effect on internet addiction. Additionally, negative emotions had no significant effect on meta-mood but meta-mood had effect on internet addiction. Likewise the analyses revealed that assumed path model was applicable to high school girls as well. In high school girls, negative emotions had both significant effect on internet addiction through the mediation of metacogniton and direct effect on internet addiction. Also negative emotions had no significant effect on meta-mood but meta-mood had effect on internet addiction. Base on the results, the implications and limitations of this study were discussed.