Clark與Watson（1991）焦慮與憂鬱的三元模式及後續相關理論（Mineka, Watson, & Clark, 1998）對焦慮疾患與憂鬱疾患的高共病率現象提出了解釋：兩疾患高共病率之因乃共同擁有負向情感共同因子，而憂鬱疾患因擁有低正向情感特殊因子使之與焦慮疾患有所區辨。然而透過文獻回顧已知社交互動焦慮疾患與憂鬱疾患皆擁有高負向情感與低正向情感兩類因子（Hughes, Heimberg, Coles, Gibb, Liebowitz, & Schneier, 2006），故目前依三元模式及其相關文獻的架構（Brown, Chorpita, & Barlow, 1998; Hughes et al., 2006; Kashdan, 2002），尚未找出得以區辨社交互動焦慮、憂鬱兩疾患不同之因子。本研究即以三元模式裡已架構的一般因子負向情感、特殊因子正向情感，再加入特殊因子害怕負向評價、以及獨特因子害怕正向評價，來建構社交互動焦慮與憂鬱的階層特徵預測模式：負向情感與正向情感屬於高階因子，為影響著社交互動焦慮與憂鬱的脆弱因子；害怕負向評價與害怕正向評價屬為低階因子，是受到社交互動焦慮與憂鬱影響的症狀向度，其中害怕正向評價即具有能區分社交互動焦慮與憂鬱兩疾患不同之區分因子概念，屬於社交互動焦慮的獨特因子。本研究主要以大學部學生為樣本，共計收取566份問卷，再進行結構方程模式統計分析。結果支持社交互動焦慮與憂鬱的階層特徵預測模式之架構，害怕正向評價為社交互動焦慮的獨特因子，能作為社交互動焦慮、憂鬱間的區分因子。然而本研究假設之一：兩疾患對害怕負向評價此特徵的預測力不同，則在統計分析中未達顯著。最後，提出本研究貢獻與其在臨床上的應用，並進一步探討本研究可能的限制，以及未來研究方向。 / Clark and Watson’s (1991) tripartitle model of anxiety and depression and Mineka, Watson, and Clark’s (1998) an integrative hierarchical model of mood and anxiety disorders explain why the comorbility of anxiety and depression (unipolar mood disorders) is high: the reason of high comorbility of anxiety and depression is these two kinds of disorders contain commom factor—negative affect. Besides low positive affect can differentiates depression from anxiety,that is depression contains low positive affect, but anxiety doesn’t. But from research review, both social interaction anxiety and depression associate with negative affect and low positive affect (Hughes, Heimberg, Coles, Gibb, Liebowitz, & Schneier, 2006). Given this finding, on the structure of tripartite model and other relevant studies (Brown, Chorpita, & Barlow, 1998; Hughes et al., 2006; Kashdan, 2002 ), until now the differential factor of social interaction anxiety and depression is not found. In this study, the factors of tripartite model: a general factor—negative affect, and a specific factor—positive affect, are included. Besides, a specific factor—fear of negative evaluation, and a unique factor—fear of positive evaluation, also are added to our research to build the hierarchical characteristic predictor model of social interaction anxiety and depression. In the hierarchical characteristic predictor model, negative affect and positive affect are higher order factors that influence and could be vulnerabilities to social interaction anxiety and depression; fear of negative evaluation and fear of positive evaluation are lower order factors that are influenced by social interaction anxiety and depression and are dimension of symptoms. Fear of positive evaluation is a unique factor of social interaction anxiety, it accounts for the diversity of these two kinds of disorders and is a differentiable key factor. The participants were college students, and the sample consisted of 566 individuals. The data were examined by structural equation modeling. The results were that most of the hypotheses of the hierarchical characteristic predictor model of social interaction anxiety and depression were supported by data analysis. One of the hypotheses: fear of positive evaluation is a unique factor of social interaction anxiety and is a key factor that can distinct social interaction anxiety from depression , was also proved. But one of the other hypotheses: fear of negative evaluation containing amounts of variance attributable to social interaction anxiety and to depression are different; social interaction anxiety contains a more component of fear of negative evaluation than depression does, in this study, the difference was not significant different. Finally, discussing this study’s contribution, practical application in treatment, and the limitations, we give some directions and suggestions for the future research.