本研究探討臉書使用者的使用動機以及使用行為對於社會資本之生活滿意度、人際信任與公民參與三個層面上的直接與交互作用影響。本研究以科技部2018年台灣傳播調查資料庫進行二手資料分析。結果發現不同的臉書使用動機對於社會資本面向的影響顯現差異情形，而使用動機和使用時間長度為確實對於社會資本的不同面向具有交互的作用。新資訊科技對於社會的影響為正面或負面端賴使用的動機與型態。為了消遣娛樂使用臉書或長時間地浸淫在臉書世界中不僅降低社會信任感也降低生活滿意度。但是如果為了工作上或維持人際關係使用臉書，並且在臉書上積極地主動互動則對於公民參與行為具有正面的效益。

This study examines the direct and interactive effects of Facebook usage, motivations, and interaction types on three dimensions of social capital: life satisfaction, interpersonal trust and civic engagement. The author uses data from Taiwan Communication Survey (TCS)’s 2018 national survey to test five hypotheses. Results of the analysis revealed that Facebook’s impact on social capital was contingent upon the specific usage and motivations of users. Using Facebook for pure entertainment was found to be negatively related to interpersonal trust and life satisfaction, while using Facebook to satisfy needs of social connection and relationship maintenance was found to be positively related to civic engagement. This study also found that the association between Facebook use and social capital variables were moderated by motivations.