口碑一直以為都是企業行銷的重要利器，而同時也是要害之一，且隨著網路的發達和社群網路的發展，對企業的影響也越來越大。而近幾年在媒體中開始出現一個新名詞，用來形容負面口碑在社群媒體中傳播的現象-線上口碑風暴(Online Firestorm)。 線上口碑風暴的相關研究相當的稀少，而在許多口碑的相關研究中也未多著墨，但隨著社群媒體的發展，此現象已越來越普遍，因此有研究探討的價值，所以在本研究中將先定義出線上口碑風暴，並以Google搜尋趨勢設計出測量線上口碑風暴的方式，以利將其從負面口碑的傳播分辨出來，並利用這樣的方法找出六個線上口碑風暴的個案來進行研究，配合Coombs的印象修復理論來進一步分析。 研究結果發現，可以將線上口碑風暴依成因分成「過去不好的服務或產品體驗」、「錯誤的時機情境」和「不適當的聲明或宣傳」，而各類別的最佳回應策略在文中有詳細講述。另外，當企業使用的回應策略越多時，線上口碑風暴持續的時間就可能越久。影響線上口碑風暴的因素有很多，經本研究的討論分析後，發現「負面訊息傳播的平台」、「回應策略的運用」和「企業的規模和性質」為最會影響線上口碑風暴的因素。 / Word-of-Mouth (WOM) has been a major marketing tool to the enterprise, but could also be one of its threats. With the development of the Internet and social networks, the impact of WOM on enterprises is also growing. In recent years, the rapid propagation of negative Word-of-Mouth in social media has gained much attention in media and is named “Online Firestorm.” Academic studies about Online Firestorm are rare, and researchers of Word-of-Mouth have not investigated it. Giving the development of social media, this phenomenon has become increasingly common. Therefore it is important for companies to know and better handle it and for researchers to investigate this new issue. In this study, we will define and measure Online Firestorm though Google Trends. We will also collect data from six cases and analyze how different responding strategies may result in different outcomes. Research found that Online Firestorm can be categorized into “past bad service or prouduct experience”, “bad timing scenarios” and “inappropriate statements or propaganda” according to the causes of the storm. The best response strategies to all kinds are described in the text. In addition, when used more response strategies, Online Firestorm duration may longer. There are many factors affecting the Online Firestorm, after the discussion and analysis found that "negative information dissemination platform", "the using of response strategies" and "the scale and nature of the enterprises" and as the factors that most likely to affect the Online Firestorm.